Should we use metronome when practice..read this

[johnmar78]

Folks, found this on the net,,,have a full reading and tell me what you think, yes or no use of metronome.

https://en.wikipedia.org/wiki/Metronome

eg, It mentioned that some musicains thinks use of metronome is CONTRAVISIAL tool for music interpretation..

My teacher said to me that metronome was invented to CHECK the "beat and tempo mark only and was not designed for " practice" for a long period...

Have your say folks....

[jayeckz]

You can use it however you like!

My teacher said to me that metronome was invented to CHECK the "beat and tempo mark only and was not designed for " practice" for a long period...

Keyword is INVENTED.

[johnmar78]

yes,,,, invention  at least we get two things out of metronome= Control and Precision nothing else....

[sleepapnea]

I always use the metronome.

Its good for control, precision/accuracy, slow practice, fast practice, medium practice, increasing speed. It doesn't take away from your musicality unless you let it - in order to employ tasteful rubato, etc you need to have the piece totally under your control first.

[timothy42b]

Sure, there's a lot of controversy, just do a search right here.

I am a fan.

There are many here who are not. 

In a large number of cases (but not all) those who oppose metronome use are those who found it difficult.  Some of those can play with good time, some cannot. 

If you are going to work commercially, you MUST be able to play with a click track.  Period.

The accusation that it produces mechanical performance would seem to be unfounded.  I hear 10,000 performances with sloppy time for every 1 with mechanical time.  Rubato means slow down for the hard parts and speed up for the fun parts - I could live with that, as predicable! 

Many people attempt to play with a metronome and give up.  Like a mirror, it sometimes tells you unpleasant truths.  Other instrumentalists, singers, etc., spend more time playing in ensembles and learn to match tempos, but solo pianists may have less opportunity to do so and absent a metronome may never learn. 

Something I've just noticed in the past month, and am working on myself:  many people find it easy to play at the same speed as the metronome.  However that doesn't mean they are actually playing precisely with it.  That is a much more difficult task.  The click of the metronome should be covered by the attack of the note, and disappear. 

One metronome use that I think is dangerous is the incremental speed up to acquire technique use.  This builds speed walls. 

[pianowolfi]

No good classical pianist ever interpretes music metronomically. But all of them are able to play in sync with the metronome, if they choose to do so for any reason.

[timothy42b]

No good classical pianist ever interpretes music metronomically. But all of them are able to play in sync with the metronome, if they choose to do so for any reason.

While young.  It is a skill that fades with age, if not periodically refreshed.  And one that soloists do not always have in abundance.   (and don't get me started on church organists!)

[j_menz]

Rubato means slow down for the hard parts and speed up for the fun parts - I could live with that, as predicable! 

It may mean that in (bad) practice, but it definitely does not mean that when properly applied. That "definition" of rubato is the source of more crappy performances (and mopre excuses for them) than most other things.

On the subject of metronomes, I would personally like to see them all piled up somewhere and (un)ceremonially burnt.

[rachmaninoff_forever]

I only use metronome to see how fast or slow I'm playing something.

[johnmar78]

thanks for your inputs, gals and guys,,,,more please..next....

Tim42, "the click of metronome should dissapeared with teh attack of the note"-thats is so true, I like it.

[nickadams]

The click of the metronome should be covered by the attack of the note, and disappear.   

This is very difficult but hopefully practice makes perfect!

[quantum]

IMO, playing with the metronome fosters a dependance on a time keeping device, where such device takes precedence and imposes suppression of all other musico-expressive, communicative and organizational aspects of the music.  The cage of subservience renders inert a musicians sensitivity to his/her aural, acoustical, and spacial awareness in preference to a radically rigid system of organization that is incapable of listening and actively evaluating the sound world as it is created in-the-moment.  What I believe the listener is really after is the foundational grounding of a tight groove providing a solidity of delivery, along with a sense of rubato that encapsulates the musical expression.

[iansinclair]

While young.  It is a skill that fades with age, if not periodically refreshed.  And one that soloists do not always have in abundance.   (and don't get me started on church organists!)

Oh dear me.  Well, you asked for it.  I was, until I retired, a church organist (Minister of Music/Choir Director -- pick your title).  Almost 50 years.  Until you have had the rather interesting job of accompanying a processional or recessional hymn in a moderately sized hall -- my last job was in a hall over 300 feet (100 meters) from end to end, with a reverb time on the order of ten seconds and with parts of my instrument as much as 200 feet from each other, and keeping yourself, the congregation, the choir, and the celebrants all on the beat at a steady tempo, you have absolutely no clue as to the level of tempo sense and stability required of a "church organist".  I will admit, however, that some "church organists" are, perhaps, not of the highest quality, being distinguished much more by their dedication to a rather difficult and terribly under appreciated job than by technical brilliance.

However, until you have given the job a shot, 50 weeks a year, a minimum of one service per week (it can reach two or three a day in a larger church!) (plus funerals, weddings, festivals, and what ever), much of it with less than a week's notice as to the hymns (it is not an accident that sight reading and improvisation on a theme are regarded as essential skills)...

As to whether or not to use a metronome -- my reaction would be "sometimes".  It can be valuable to check one's tempo choice against the composer -- when the metronome marking is the composer's, and not the editor's.  It is not really a handicap in baroque music, and I might go so far as to suggest using it at times when practicing J. S. Bach or Buxtehude etc.  If one doesn't routinely practice scales, arpeggios, and similar torture scores, in fact, I would suggest playing at least some Bach every day -- at least partly for developing tempo stability -- and using the metronome for that, or your scales or your Czerny isn't a bad idea, until tempo stability is second nature.

It is useless, in my view, for pieces involving polyrhythmns or complex subdisvision, except to mark the principle beat, and it is downright lethal in vocal music and accompanying.

[nystul]

IMO, playing with the metronome fosters a dependance on a time keeping device, where such device takes precedence and imposes suppression of all other musico-expressive, communicative and organizational aspects of the music. 

Only if you use it at all times, which would be ridiculous.  But some people need to gain that sense of grounding, learn how to subdivide, etc.  In high school I played with a bass drummer who couldn't find steady quarter notes if you beat him over the head with them. 

[49410enrique]

meh..i'm not sure it really matters either way. what i mean is, use it. if it helps you play better and learn, great use it. if it doesn't help you, then don't. doesn't really seem to matter all that much why  or how or when or ......... just play with it if you find a use for it, keep the 'tool' in your 'tool box' if you don't see a big benefit or need don't keep it in your box. that' s how i look at a lot of these things, i.e. just try it, evaluate, adjust as neccessary, move on.

[timothy42b]

Oh dear me.  Well, you asked for it.  I was, until I retired, a church organist (Minister of Music/Choir Director -- pick your title).  Almost 50 years.  Until you have had the rather interesting job of accompanying a processional or recessional hymn in a moderately sized hall -- my last job was in a hall over 300 feet (100 meters) from end to end, with a reverb time on the order of ten seconds and with parts of my instrument as much as 200 feet from each other, and keeping yourself, the congregation, the choir, and the celebrants all on the beat at a steady tempo, you have absolutely no clue as to the level of tempo sense and stability required of a "church organist". 

It is my theory that it is precisely that degree of difficulty that erodes the time sense of organist. 

I can't prove it.

I can prove by a substantial amount of anecdotal evidence and personal observation that it is common for church organists to lack the ability to hold a steady tempo.  However, they are a dying breed, and we are glad to get one at all! 

There was an interesting study done on golfers.  As we mature, our ability for fine timing fades, and fine timing is critical to the golf swing.  A little early or late, and the angle causes the ball to squirt in unpredictable directions.  One group of golfers read tips from golfing magazines while another group spent equal time doing basic music rhythm exercies.  The rhythm group improved while the tips group did not.  So I conclude that even aging people like myself can retain pulse, but it may ntake some focused work. 

[iansinclair]

It is my theory that it is precisely that degree of difficulty that erodes the time sense of organist. 

I can't prove it.

I can prove by a substantial amount of anecdotal evidence and personal observation that it is common for church organists to lack the ability to hold a steady tempo.  However, they are a dying breed, and we are glad to get one at all!
... 

You may be right (you certainly are about being a dying breed); it takes a fiendishly strong sense of tempo to hold steady (and, I might add -- and this isn't really a compliment to either me or other long term MofMs -- an almost equally fiendishly strong ego (i.e. you have to think "I'm right, and all the rest of you lot are wrong -- so there!")).  Particularly in a larger space, or with a larger instrument (spatially large) there is a terrific time delay involved, and unless the organist is really confident -- really confident -- the tendency to slow down is almost overwhelming.  To put it in perspective: where I last played (300 feet) the time delay between the organist hitting a note and hearing the choir at the start of the procession hitting the same note is half of a second -- which equates roughly to them seeming to be about a quarter note behind at a typical fast hymn tempo.  All you can do is grit your teeth and keep chugging, and you are quite right that a lot of people (particularly pianists who've been dragooned into the job because they happen to play a keyboard instrument!) have a lot of trouble with it.

And, of course, some instruments are worse than others.  Some have the organist more or less literally in the instrument, with tracker action.  With those there is almost no time delay (although it is still more than a piano!).  Others are either spatially large -- as I noted, one of the instruments where I had my last job was spread out over about 200 feet -- or otherwise have significant time delays from the key to the sound due to the nature of the action.  It is not at all uncommon for your fingers or feet to be a note or two ahead of the heard sound on many instruments, which is disconcerting until you get used to it.

I might add that a good Minister of Music should have a thoroughgoing knowledge of the theology and practice of his or her church (not, perhaps, sufficient for ordination, but close) as well as its music and liturgy.

It is, in short, not something which a pianist, even a very fine pianist, can just drop in on and do a good job at.

Conversely -- and this is certainly true of my own experience -- being a decent organist does not guarantee that one will be any good at all as a pianist!  I've been retired five years now, and practice as diligently as seems reasonable at my age, but I still have a lot of work to do to become a good pianist.  Almost the only thing the instruments share is a keyboard.  Which is a different size and feels completely different, so it isn't that much help!

[quantum]

Only if you use it at all times, which would be ridiculous.  But some people need to gain that sense of grounding, learn how to subdivide, etc.  In high school I played with a bass drummer who couldn't find steady quarter notes if you beat him over the head with them. 

The fact remains there are people that rely so heavily on the metronome, it consumes much of their practice time.  Is  this ridiculous - absolutely so!  This is in no way exclusive to new learners or students in their formative years. I know of Juilliard grads that are very dependent on the metronome to fish out flaws in their playing. 

[ted]

Never used one and have never seen any point in them. I do own one, which a well meaning relation bought me as a kid. Most of the rhythms I find exciting are not regular anyway, so the effect of a metronome would be totally negative. I have never had any problem keeping a regular beat if that is what is really needed, which these days isn't very often. Playing a lot of swing, ragtime, stride and the like since very young has probably helped me there.

[Derek]

I'm similar to Ted in that the music I most enjoy playing doesn't require metronomic practice. (e.g. my own improvisation) However, I have at times tried my best at learning to play Beethoven (for example) the "proper" way. Having not had rigor or pressure of any kind at any point in my musical youth, I find that I am quite literally incapable of playing a lot of classical music *without* practicing with a metronome. I think for highly metronomic (go figure) music it is a necessity. For music with a lot of rubato and polyrhythm (e.g. nocturnes with very free right hand melodies) it might not be as useful.

I also play boogie, which is highly metronomic. I've been toying with it for years, but it hasn't created an internal metronome in me. My dad is so amused by my inability to stay with him in duets that he made a track where he played a duet with himself, intentionally making one of the two left hands out of sync with the other in imitation of me. So, I sometimes use a metronome to attempt to tighten my boogie.

[timothy42b]

I've been youtubing drum lessons this week. 

(I have to play mallets this weekend, and I haven't touched a set in several years.  So a little review won't hurt.  Besides drums are kinda fun.) 

There are 100's of drum lessons and tutorials, some good and some bad.  There may be more on drums than the rest of the instruments combined. 

I have yet to find one that didn't insist practicing with the metronome was essential. 

[perpetual_dan]

As an alternative to metronome today I ran a digital piano into notation software via MIDI. I set it to allow some rubato. Comparing the printed music with the transcription was quite a good way of revealing timing errors that would be hard to understand while playing even with a metronome.

[pianoisthebest23]

Occasionally I use the metronome, but only to see how fast a song is supposed to go. I like to use a little bit of rubato when I play, so the metronome often hurts my practice. To me, playing at a precise metronome speed sounds a little too perfect.

[oxy60]

thanks for your inputs, gals and guys,,,,more please..next....

Tim42, "the click of metronome should dissapeared with teh attack of the note"-thats is so true, I like it.

I can control the volume of the metronome and yes it will fade out. Then I will only see the blinking light. Remember, if you can't keep time you won't be able to play in an ensemble...

[larapool]

I'm inclined to agree with my professor who says the metronome is an incredibly useful tool.  I do not understand why people put the device down.  It is only bad if you develop a dependence on it.  It should not be used as a crutch.  Furthermore, for pieces that require rubato (Chopin is the perfect example for this), I think the best way to approach practicing those pieces is to play it at a strict tempo and *then* add rubato, because once you can play the piece at a rigid tempo, you will be able to determine how and when to slow down/speed up, and harder passages will be executed more fluidly and naturally than if you were to practice without a metronome.

[timothy42b]

Occasionally I use the metronome, but only to see how fast a song is supposed to go.

am
That's a valid use of the metronome, to check your average speed.

I use it to check instantaneous speed.  I want my note to start precisely when it needs to, and the metronome practice is one way to accomplish that.

But i don't just play piano.  I play brass instruments, where a coordination of breath, fingers, and lips are required to start the note precisely on the click, and I teach handbells, where a motion of several FEET precedes the start of the note.  And I play in ensembles, where I CANNOT use my own concept of rubato, but must match an external time.

There is no need to play with the metronome if you have those skills.

But check yourself out.  If you CANT play with the metronome, something is wrong.  Learn it. 

[oxy60]

Oh dear me.  Well, you asked for it.  I was, until I retired, a church organist (Minister of Music/Choir Director -- pick your title).  Almost 50 years.  Until you have had the rather interesting job of accompanying a processional or recessional hymn in a moderately sized hall -- my last job was in a hall over 300 feet (100 meters) from end to end, with a reverb time on the order of ten seconds and with parts of my instrument as much as 200 feet from each other, and keeping yourself, the congregation, the choir, and the celebrants all on the beat at a steady tempo, you have absolutely no clue as to the level of tempo sense and stability required of a "church organist". 

Until that sentimental hymn starts to drag and we need to "pull" everyone along...

Your remarks brought back some wonderful memories of my experiences. One moment comes to mind during a hymn with several verses and for a moment I lost count of which verse we were on. You were a real champion to have stuck with it for fifty years! You deserve a real rest.

[ted]

I also play boogie, which is highly metronomic. I've been toying with it for years, but it hasn't created an internal metronome in me. My dad is so amused by my inability to stay with him in duets that he made a track where he played a duet with himself, intentionally making one of the two left hands out of sync with the other in imitation of me. So, I sometimes use a metronome to attempt to tighten my boogie.

As a kid I used to lie on the floor between the speakers of two tape recorders, each playing different things, or the same thing out of sync in varying degrees. I find the convergence and divergence of multiple rhythmic, harmonic and phrasal streams peculiarly exciting and it is an effect which has deeply penetrated my improvisation. Surprisingly, it isn't all that hard to do once the trick is learned of letting the fingers think for themselves.

[pianoyutube]

My teacher said to me that metronome was invented to CHECK the "beat and tempo mark only and was not designed for " practice" for a long period...

I don't know exactly why was the metronome invented, but I agree totally with your teacher. I use it only to check my speed. I trust my inner sense of rythm, and I use the metronome as a reference of how fast do I play a piece and how fast is it supposed to be played.

[johnmar78]

wooh, Pianoyoutube...this topics becomes more and more addicted. Hummmmm, metronome on, hummm metronome off.  

[timothy42b]

. I trust my inner sense of rythm, and I use the metronome as a reference of how fast do I play a piece and how fast is it supposed to be played.

Do you ever play in an ensemble, such that you have to play exactly WITH an external time source, and cannot float along on your inner pulse? 

I ask because many, many pianists never do this, and have no idea that their inner pulse is not as steady as they think.

If you do, do you ever record your performance and check that you are really doing what you think you are doing?  I've seen many players who drag or rush and emphatically deny doing so, but the recording does not lie. 

The inner pulse needs occasional calibration, and for this the metronome is useful (though not needed if you are an active gigging musician, you're already playing in real time). 

I find that 3 out of 4 church organists have an inner pulse bad enough that it is uncomfortable to play or sing with them.  They do not know it and can never be convinced of it.  If they did any metronome work at all it would become clear. 

[nickadams]

I have a question maybe someone can help me with.

If a song calls for 80 bpm how do you know if you are playing without a metronome? Do some people have that good of internal tempo that they can do that? Also, if you are playing a piece without a metronome and you get your timing off, how do you get back to the right tempo without a metronome? Do you just speed your playing back up and then think *ahh that feels like 80 bpm let's settle here*?


I'm a new piano player with horrible internal tempo so any help is appreciated!

[pianoyutube]

Do you ever play in an ensemble, such that you have to play exactly WITH an external time source, and cannot float along on your inner pulse? 

If you do, do you ever record your performance and check that you are really doing what you think you are doing? 

I've played in an ensemble, only jazz and pop styles. No trouble with rythm (after some experience, of course), maybe because you have to improvise, and you can recover if you get lost, just following the bass. Playing classical music,  is more difficult, of course.

About recording your own performance, thanks for commenting this subject in this thread. I always do it. With every single piece. And I check my rythm with the recording (rythm, dynamics, sound, etc..), and for me that's the best way to develop my inner sense of rythm. Much better than the metronome.

[pianoyutube]

If a song calls for 80 bpm how do you know if you are playing without a metronome? Do some people have that good of internal tempo that they can do that? Also, if you are playing a piece without a metronome and you get your timing off, how do you get back to the right tempo without a metronome? Do you just speed your playing back up and then think *ahh that feels like 80 bpm let's settle here*?

Well, if I need to play exactly at 80 bpm, I start the metronome, and feel the rythm 3/4, 4/4 or whatever, at that speed. When I've got it, I stop the metronome. If I get my timing off, I can start and stop the metronome again ... As needed. For me the metronome is a useful tool, used in this way.
Anyway, I prefer to listen to some recordings, and catch the rythm. I've discovered that Barenboim, Gould, Ashkenazy ... play at different speeds. That's very interesting, don't you think?

[danhuyle]

To keep rhythm under control like in slow movements of sonatas. Without question, the metronome does save time and frustration.

I've used the metronome to play through short pieces from start to finish depending on what the piece is. Some pieces you can do that. Then there's pieces where you'd want to get comfortable with notes and technique, then practice with the metronome to keep the rhythm solid.

More importantly, when I find that I'm not ready to use a metronome, like playing the 2nd movement in Mozart Sonata k457, I've got a brief idea on how the rhythm should go so that even at a very slow tempo, the sense of rhythm is still present. Perhaps it could be better to ignore the rhythm to get the familiar with the notes, then slowly metronome each phrase in quaver pulse, then crotchet beats?

And yes, listen to recordings they help develop rhythm too.

[oxy60]

I have a question maybe someone can help me with.

If a song calls for 80 bpm how do you know if you are playing without a metronome? Do some people have that good of internal tempo that they can do that? Also, if you are playing a piece without a metronome and you get your timing off, how do you get back to the right tempo without a metronome? Do you just speed your playing back up and then think *ahh that feels like 80 bpm let's settle here*?


I'm a new piano player with horrible internal tempo so any help is appreciated!

Record yourself. Then count the bests per minute. Adjust as needed.

Another trick is to check you heart rate which could be in the 80 range. Then you just play with your heart beat. Plus or minus 5 bpm is not critical at your level. When you get to difficult pieces 5 bpm could be the difference in whether or not you can even play the piece.

[johnmar78]

I have a question maybe someone can help me with.

If a song calls for 80 bpm how do you know if you are playing without a metronome? Do some people have that good of internal tempo that they can do that? Also, if you are playing a piece without a metronome and you get your timing off, how do you get back to the right tempo without a metronome? Do you just speed your playing back up and then think *ahh that feels like 80 bpm let's settle here*?

Pal, if you practice at 80 for a while, your muscle memory will play at that timing. I did few experiments already, while doing 132, and when i did my recording the paly back beat is 132, if not 126-136. But very close thst is negliteble.
I'm a new piano player with horrible internal tempo so any help is appreciated!

[timothy42b]

I've used the metronome to play through short pieces from start to finish depending on what the piece is. Some pieces you can do that. Then there's pieces where you'd want to get comfortable with notes and technique, then practice with the metronome to keep the rhythm solid.

Yes.  Excellent suggestion.  The metronome keeps you honest here.  There is a tendency to delay between sections of a short piece that is impossible to detect on your own.  It is easy with the metronome, more so than the recording. 

[nickadams]

Is it bad to tap your foot with the beat to help keep time when you're playing?

[johnmar78]

Is it bad to tap your foot with the beat to help keep time when you're playing?

I agreed with you  totally, especially doing recording.

[faa2010]

I have started to use the metronome, and if you know how to get the beat, I am sure you are going to be in the right track. One of the issues one needs to deal also is playing more than two notes in one beat.

Just one question (it may be simple, but it is important), can metronome help with giving a smoother playing?

[oxy60]

Yes. Smooth playing is having all notes of the same value played at&for the same time. All 1/8's should be of the same length, etc. When they are different your playing either sounds rushed or hesitant. With time the metronome will become your friend.

And when you are asked to sit in with your friends who have a garage band you will be able to blend right in...

[nickadams]

I agreed with you  totally, especially doing recording.

sorry i don't get what you mean? I was wondering if tapping your foot to keep the beat while playing is a bad habit?

[jayeckz]

Yes. Smooth playing is having all notes of the same value played at&for the same time. All 1/8's should be of the same length, etc. When they are different your playing either sounds rushed or hesitant. With time the metronome will become your friend.

All the hallmarks of great mechanical playing.  ISO midis.

[j_menz]

Yes. Smooth playing is having all notes of the same value played at&for the same time. All 1/8's should be of the same length, etc. When they are different your playing either sounds rushed or hesitant.

Yikes! That's not smooth, that's just awful!

With time the metronome will become your friend.

Some friendships are best avoided. This is one of them!

And when you are asked to sit in with your friends who have a garage band you will be able to blend right in...

If that is your aim, then that is probably fine.  If you are looking to play much else though.....

[ajspiano]

Yes. Smooth playing is having all notes of the same value played at&for the same time. All 1/8's should be of the same length, etc. When they are different your playing either sounds rushed or hesitant.

My god! - not that we shouldnt have generally even playing, but if you actually manage to achieve "all the same" you will sound like a quantized robot, and no ones wants to hear a robot - except trance fans maybe, even then it'd be better played live by a human with at least some variation.

Consistent beat, or at least a beat that can be "felt" by the listener is far more important than perfect note lengths throughout - and if you have that you'll fit right into that garage band as well.

[timothy42b]

Consistent beat, or at least a beat that can be "felt" by the listener is far more important than perfect note lengths throughout - and if you have that you'll fit right into that garage band as well.

If you can't play with a metronome you aren't ready to play with a garage band either.

Bad as they are, you'll get laughed off the place. 

Not saying you have to play WITH a metronome all the time, or even often - but it's a skill you MUST have if you're ever going to play with anybody else.

And I can tell you from long experience gigging that a lot of pianists who THINK they have that skill really DON'T. 

[ajspiano]

If you can't play with a metronome you aren't ready to play with a garage band either.

Bad as they are, you'll get laughed off the place. 

Not saying you have to play WITH a metronome all the time, or even often - but it's a skill you MUST have if you're ever going to play with anybody else.

And I can tell you from long experience gigging that a lot of pianists who THINK they have that skill really DON'T. 

I'm working on the premise that if you can "feel" the beat then playing in time with a mentronome or anything else shouldnt be a challenge. And I agree that there are pianists (or just musicians generally that think they can, and really cant. I've been in plenty of bands as either pianist, guitarist or drummer..   its the worst when the one that can't is the drummer, something I had the misfortune to have to deal with for a gig once in the backing band with an elvis impersonator 

And just to clarify, I know people who can play with a metronome and still have no internal sense of beat/rhythm, so its really not a be all and end all skill for timing.

[j_menz]

OK, so I've been pretty dismissive of metronomes in this thread, so let me take a step back.

A pianist needs to be able to play with rhythm, pulse and timing.  If playing with others, you need to match the rhythm, pulse and timing of those others.  I cannot see that that is at all arguable (or that anyone is trying).

With the possible exception of modern dance music (and then solely for the convenience of mixers and djs) music is played best when that pulse, rhythm and timing is, to a greater or lesser degree depending on the style of the piece, flexible in line with the musical demands of the piece.  In classical and jazz (and no doubt much else), no halfway decent performance ignores this.  For ensembles, obviously there has to be a common approach, meaning that an individual player has to be in time with the common pulse and rhythm (or in some instances, such as a jazz soloist, interact with it).

In order to achieve the ability to do this, a pianist needs to develop a highly accurate sense of pulse, rhythm and timing. That needs to be completely internalised. It also needs to be well enough ingrained to allow it to be responsive to the demands of ensemble playing, whether that be metronomically exact or in line with a common ebb and flow.

Many pianists find this problematic (particularly in their early development), and some kid themselves that they have this ability.

A metronome may be a useful device to assist in developing this ability, or in checking that one has it to the degree required.  If a person finds that to be the case, then by all means use it.  But ONLY for the purpose of that development.

A metronome may also act as a crutch, being used as a substitute for that internal development, and possibly hindering it. In these cases, it's regular or routine use should be avoided at all costs. It may still be used occassionally and intermittently to assist with difficult passages, or to check progress.

The important thing is the end (a highly developed internal sense of pulse, rhythm and timing), not the means by which it is achieved.

[timothy42b]

A metronome may also act as a crutch, being used as a substitute for that internal development, and possibly hindering it. In these cases, it's regular or routine use should be avoided at all costs.

That is certainly possible.

But do we have any evidence it is so? 

Particularly among pianists, significant use of a metronome has been a rarity, so it would be pretty hard to gather data.

Other instrumentalists make much greater use of the metronome.  Do we have any data this hurts them?

Some instrumentalists make extensive use of playalongs.  In the old days everybody learned by playing along with records.  They were using external time, it just didn't have a click going.  Did that hurt them? 

Do we find any correlation between those who have difficulty playing with a metronome and those who fear it will make them mechanical?  (Aesop called this fox and grapes.)