Bach struggling

[billybraga]

Im a intermediate student, and im getting contact with the easiest Bach pieces rn (i have done pretty much of the anna magdalena bach's repertoire). Atm, im practicing bach 2 voices inventions 8 and 4. Its normal to get bored playing it? I know that Bach's pieces has a lot to add to my musical knowledge, but i prefer spending most of my practice time learning some chopin and beethoven, instead of Bach pieces. What can i do to get my bach's practice sessions more fluid, without getting tired?  Am i practicing it wrongly?

[anacrusis]

Hello! It is a very good idea, as you say, to practise some Bach. Bach is some of the best things to practise if you want to increase your skill and control over both hands. I have two thoughts regarding your problem:

- Maybe you can motivate yourself to practise a bit of Bach regularly by reminding yourself that it will greatly benefit your skill in playing, which will benefit your Beethoven and Chopin playing too. Both Chopin and Beethoven admired Bach and some of the things that appear in their music become easier to play if you know some Bach. Bach can be tricky, which might contribute to you feeling tired by it. This means your brain is working hard and making new connections that will benefit you later!

- Maybe you can find a Bach piece that you really like and excites you, and this will help motivate you working on it. I know many people like this piece by Bach (you don't have to play it this fast, it is still very beneficial to learn even if you play it slowly):

Are there any Bach pieces you know you like? How do you feel about the inventions you are playing right now?

[billybraga]

I never listened much bach pieces, but i like very much that preludium  . About these pieses, im feeling that the days pass, but  im not making any progress though. I can easily perform both hands separately, but when it comes to group these counterpoints together, the things get embarassed
I kinda demotivate, because if im not growing up on the easiest songs, imagine when i get to the most difficult ones  .

[j_tour]

I never listened much bach pieces, but i like very much that preludium  . About these pieses, im feeling that the days pass, but  im not making any progress though. I can easily perform both hands separately, but when it comes to group these counterpoints together, the things get embarassed
I kinda demotivate, because if im not growing up on the easiest songs, imagine when i get to the most difficult ones  .

I don't know what to say, but just an anecdote:  it wasn't all that long ago that I become so immersed in even "simple" pieces of Bach I'd be going to sleep or waking up and have the whole of, say, the first two-part invention "playing" in my head.  With full consciousness, even in a liminal state:  not just some impression of some random style.

Completely involuntary.  And I'd played a good bit of Bach since younger days, but this was a different approach to me that only came with repeated listening, also, at an adult age.  And, yes, I did go back to the two-part inventions and the sinfonie, which I still use as memory exercises as well as the equivalent of doing scales, although I do those too.

Maybe counterpoint is so different than your other stuff that you need time to let the lizard brain assimilate it. 

Techniques vary, especially mental practice or approaches, but, not to sound like some would-be guru, if it takes that long, then you should walk that length.  If you want it, that is. 

There's no shortcuts.  There are some ways of making practice and conception of a piece more efficient, but that's not really applicable here, I don't believe.

[brogers70]

I never listened much bach pieces, but i like very much that preludium  . About these pieses, im feeling that the days pass, but  im not making any progress though. I can easily perform both hands separately, but when it comes to group these counterpoints together, the things get embarassed
I kinda demotivate, because if im not growing up on the easiest songs, imagine when i get to the most difficult ones  .

It's hard to get used to playing counterpoint. It's totally normal to be able to play each line separately and then have a devil of a time putting them together. If the goal you focus on  is to play the whole piece, you may well get demotivated.

So I suggest making your goal much, much smaller. Pick just a measure, or even a half measure or even just one beat, in which both voices are active. Surely after a few tries you'll be able to play that tiny fragment hands together. Don't think about how long it will take to learn the whole piece that way. Then try an adjacent fragment. Then put them together. Just focus on the small goal of getting the fragments to feel natural and comfortable. Just do that work for as long as you can without getting bored, even if it's only 10-20 minutes a day. Then do something else. Then keep doing it in small amounts every day. You'll be surprised how quickly that the fragments you can manage in a 15 minute session get longer over time. After some weeks or months you'll be moving much more quickly. The main thing is to focus on small, attainable goals and not to get psyched out by thinking about "what it all means for your likely future progress as a pianist."

[wilhelm b.]

Just some tips for your general interpretation of Bach's works:

- When there's a trill, always start it on the top note of the two- some general knowledge every interpreter should know. note that this only applies to music written in the baroque period.

- Also, Bach lived in a time where technicality and precision were valued, so if you feel like your getting a bit romantic with your musicality, just remember that the music was written to be interpreted in a sophisticated manner, rather than being given to ones pathos-centered emotions.

Best,

WB

[anacrusis]

I never listened much bach pieces, but i like very much that preludium  . About these pieses, im feeling that the days pass, but  im not making any progress though. I can easily perform both hands separately, but when it comes to group these counterpoints together, the things get embarassed
I kinda demotivate, because if im not growing up on the easiest songs, imagine when i get to the most difficult ones  .

I am glad to hear you enjoyed the piece I would do as brogers70 suggested, and work on maybe just one or two measures for a 10-15 minutes and try to sort it out, and then leave it. You might be surprised to see your progress if you keep at this for a while

[brogers70]

Just some tips for your general interpretation of Bach's works:

- When there's a trill, always start it on the top note of the two- some general knowledge every interpreter should know. note that this only applies to music written in the baroque period.

- Also, Bach lived in a time where technicality and precision were valued, so if you feel like your getting a bit romantic with your musicality, just remember that the music was written to be interpreted in a sophisticated manner, rather than being given to ones pathos-centered emotions.

Best,

WB

Of course it is possible to overdo anything, but Bach should not be played as if it is some purely mathematical, idealized meditation on the potential of different sequences of intervals. Baroque music is intensely emotional. It differs from Romantic music not by being less emotional, but by lacking dramatic progression from one emotion to another within the same movement or piece. As a rule, each piece of Baroque music expresses some single specific affect - joy, grief, anxiety, playfulness; it generally does not move through a dramatic progression within a single movement, say from, sorrow to defiance to triumph or resignation, as Beethoven might. It's hard to imagine deeper emotion or greater pathos than that in the St. Matthew Passion, and there are innumerable examples one could find in Schutz or Purcell or Monteverdi or Handel.

[ranjit]

Of course it is possible to overdo anything, but Bach should not be played as if it is some purely mathematical, idealized meditation on the potential of different sequences of intervals. Baroque music is intensely emotional. It differs from Romantic music not by being less emotional, but by lacking dramatic progression from one emotion to another within the same movement or piece. As a rule, each piece of Baroque music expresses some single specific affect - joy, grief, anxiety, playfulness; it generally does not move through a dramatic progression within a single movement, say from, sorrow to defiance to triumph or resignation, as Beethoven might. It's hard to imagine deeper emotion or greater pathos than that in the St. Matthew Passion, and there are innumerable examples one could find in Schutz or Purcell or Monteverdi or Handel.

I have always felt that Baroque music shared more similarities with the Indian raga in terms of its philosophy. It seems like it was meant to be "perfect" music in a sense, not bound by ordinary earthly emotions and goings-on. And the emotions do not change throughout the piece in ragas as well (each raga is tied to a specific emotion and time of day by definition), which is one of the points of contention of a lot of Indian listeners with Western classical -- they simply don't like the mood changing every so often within the same piece.

[lelle]

I think Bach is just as emotional as any romantic composer. The emotion is just expressed within a different framework. Listen to the c sharp minor fugue of WTC1 and don't you dare tell me it is not highly emotionally charged music 

[brogers70]

I have always felt that Baroque music shared more similarities with the Indian raga in terms of its philosophy. It seems like it was meant to be "perfect" music in a sense, not bound by ordinary earthly emotions and goings-on. And the emotions do not change throughout the piece in ragas as well (each raga is tied to a specific emotion and time of day by definition), which is one of the points of contention of a lot of Indian listeners with Western classical -- they simply don't like the mood changing every so often within the same piece.

That's interesting; I'd never noticed that similarity before.

[comma]

I remember one of my teachers saying: Play a lot of Bach and play a lot of Liszt. If you can play Bach and Liszt perfectly well, you can play everything.

[lettersquash]

Hi billybraga, that was very much my problem a few weeks ago - I thought I'd never learn the few pieces I'd set myself, particularly the counterpoint of Bach. I'm learning the Two Part Invention No.1 in C (so even easier than 8 or 4, I think). Great advice here so far, as usual. What turned it round for me was:

1. I was playing too fast. Despite knowing that you start slowly and gradually get better, eventually reaching the tempo prescribed or your own interpretation of it, I didn't realise I was pushing it too fast too early. This applies to almost everything (although some pieces can lose their sense so much if you play them very slowly that it's almost worse!).

2. Hands together is not twice as hard, or four times, more like 20 times harder. Bach counterpoint is particularly tricky (in my limited experience).

3. No matter how well I've learned a piece hands separate, it appears not to translate into better HT play (in my limited experience). This was crucial for me, mainly because I struggle a bit with reading (as opposed to learning where I put my fingers and forgetting there's a score in front of me). It was an absolute revelation when I slowed right down...no, even slower!... to the point where I was reading each and every note of both hands. It sounds obvious, but THAT is what the missing bit was - programming my brain to move both hands where they need to go at the same time, and forcing myself to read it properly. That was - as I say - VERY slow. It's a bit like when you're learning a scale and you have to switch position ("thumb under") at different times. It seems to me that only slow practice gets that coordination into my brain. I'm not sure what's happening when I play to fast, but probably I'm watching the more difficult part of the score, whereupon the easier bit messes up, and that means I'm not teaching myself to play it properly, but practising my habitual mistakes.

4. One secret for helping avoid the boredom of playing slowly is to "play" - i.e., this isn't work, it's fun, it's experimentation. I often find that playing something much slower than it's usually played opens up a whole new vista of expression possibilities, and I "play" with those. I imagine this is actually how the composer meant it to be played (and I suspect they often did as they were writing it, but forgot when they got better at it and sped up!). There's been some discussion of how emotional Baroque music "ought" to be, but I take that with a pinch of salt. I'm learning the Aria from the Well Tempered Clavier 1, and I'm amazed how many different phases of emotion it goes through in one piece - either I'm imagining that, or people who don't believe me are stone cold . Baroque expresses emotion as well in the player's interpretation, particularly in rubato (changes of tempo, little halts and swifter moments) and accenting of notes - phrasing - and that's where I can have so much fun with these while I play them slowly. Many of those interpretive touches also carry over as I increase tempo, and I don't think I'd ever discover them or fit them in later if I blasted through something at high speed.

5. Chunking - as has been said - don't keep practising bits you can play, practise the bits you can't. I play through a piece once in each session, then go back and practise the bits I stuttered over (or I stop playing through and work on those before continuing). Some sessions, if I haven't much time, I just play "those four tricky bars" and call it a day. In order to keep the shape of a piece in mind, I sometimes play the hard bits at a slow pace, then speed up through the bits I can do easily (for instance, in the 2-Piece in C, there are passages where the parts take turns, so it's almost as easy as playing HS).

6. If you have the freedom to choose pieces yourself, do ones you fall in love with. The Aria is "way above my pay grade", but I literally couldn't stop myself trying. I made it my treat after plodding through things I was bored with (before I had my revelation).

[j_tour]

That was an impressive, practical summary of approaching Bach, lettersquash

I think you hit all the main points I can think of.

Out of curiosity, are you doing the C invention with the embellishments (just some extensions added in by Bach, in alternate written version:  if I'm remembering correctly, Gould plays those on record, as does Schiff on one of his earlier recordings)?

I like your comments about finding ways to articulate even simple moments in interesting, playful manners.  I think that's something I unconsciously picked up from Gould.  A sort of insouciant way of making a simple accompanying voice gain some texture, mostly by playing with articulation (detached or legato) and some subtle modulation of dynamics in volume.

You said it right:  really just a fun, ludic bit of playing around with the unexpected.

Bravo!  Very good, comprehensive post.

[lettersquash]

That was an impressive, practical summary of approaching Bach, lettersquash

Thanks j_tour, and it's not without some significant learning from you and others here.

Out of curiosity, are you doing the C invention with the embellishments (just some extensions added in by Bach, in alternate written version:  if I'm remembering correctly, Gould plays those on record, as does Schiff on one of his earlier recordings)?

I guess you meant the Aria? In which case, yes. (If not, I don't know about them in the Two Part Invention in C.) I have a nice book called Bach Gold, in which the trills of the Aria are all expanded on a separate line above the staves for reference, although I would have struggled a lot without hearing recordings. There is one point where there's a trill in both hands (the second note in the B section), which I can't get my head round, and I might just continue to ignore the one in the left, or it might suddenly land.

[j_tour]

I guess you meant the Aria? In which case, yes. (If not, I don't know about them in the Two Part Invention in C.) I have a nice book called Bach Gold, in which the trills of the Aria are all expanded on a separate line above the staves for reference, although I would have struggled a lot without hearing recordings.

No, I was talking about the C Invention:  I think they're written out as a separate variation in the Alfred edition, probably from some notebook manuscript copy.  I know I've seen the variant written out in other editions as well.  I sometimes play that one for fun, and just play the regular version, maybe with some extra notes in the hands-separate sort of call and response section.  Just fooling around, really, for me, strictly for fun.  It's a neat piece:  I think it compares favorably to the C major sinfonia, in many ways.  Can be played at super maximum high speed, or slow, or however you want.

But, now that you mention it, that's a good call on the Aria (you're talking about the Goldberg Aria, right?):  I initially misread Bach Gold as Bach Gould and thought, to myself "That's right, Gould did get a lot of mileage out of those ornaments!"

That's a pretty challenging task, to figure out how to personalize those, or even whether to do so, versus playing them in a really "straight" manner.

here is one point where there's a trill in both hands (the second note in the B section), which I can't get my head round, and I might just continue to ignore the one in the left, or it might suddenly land.

Oh yeah, I remember that one:  kind of an odd little moment.  I don't recall exactly how I like to play that, probably changes from time to time whenever I give that a little read (or try to dig deep from memory).  (And no, I don't do the variations where the hands are crossing over doing the very quick scalar work:  they seem kind of perverse to me, and I'd really have to practice those quite a bit to have any chance).

I think that's perfectly fine to do it like you're doing:  it doesn't have to be exact.  It's just a little "extra" moment in the piece that can be fluffed over however sounds good to you.

The Bach Police Squad will surely not come looking for you! 

Come to think of it, that is a challenging piece in its own way:  everything fits together so nicely, it really needs solid musicianship to play.  Lots of decisions to be made in interpretation.  Slow?  Brisk?  Ornamentation?  Articulation?  A metronomic-type grid or using a bit of rubato? 

A very worthwhile piece, and a test for one's abilities as a craftsperson.

[lettersquash]

j_tour, yes, after I posted that I realised there certainly are ornaments in the Two Part Invention in C. And yes, I meant the Aria from the Goldberg Variations, not the WTC - I'm all over the shop!

I don't know if the edition I play (of the 2p in C) is more or less ornamented - it just has a few, like one in each of the first two phrases. I hope to record and post on the forum when it's a little more together...or maybe before, maybe we need more recordings of the process!

[j_tour]

j_tour, yes, after I posted that I realised there certainly are ornaments in the Two Part Invention in C. And yes, I meant the Aria from the Goldberg Variations, not the WTC - I'm all over the shop!

LOL!  That's a new phrase for me.

I don't know if the edition I play (of the 2p in C) is more or less ornamented - it just has a few, like one in each of the first two phrases. I hope to record and post on the forum when it's a little more together...or maybe before, maybe we need more recordings of the process!

Yeah, that's the regular one.  The "alternate" version has some kind of odd "swooping" little filagrees:  I prefer the regular one.

There is a video on youtube of, like five famous pianists doing the Invention spliced together back to back:  kind of neat.  I don't have a link, but it should still be out there.

[lettersquash]

Oh yes, I think you mean this - and I think it's just Gould who does those "filagrees", although Turek ends with a nice - er, turn? - I don't know all the terms, and Gieseking, as well as racing away like the pubs are closing, appears to play a wrong note! It's very useful listening to these, thanks. Gould's wonderful, but I can't stand his humming.

&t=145s

Yes, "all over the shop" was a bit parochial - British English, mainly Northern. I'm a Yorkshire "lad".

[j_tour]

Gould's wonderful, but I can't stand his humming.

Sacrilege!  The humming's the best part.  (Kidding). 

I don't think Gould does the complete variant, just adding a few little things here and there, but here's Schiff doing the whole variant manuscript.

Just for completeness's sake.  It appears they allow it to be embedded into websites, as far as I can tell, so that's good.

Yes, "all over the shop" was a bit parochial - British English, mainly Northern. I'm a Yorkshire "lad".

That's very good!  I like it!

It might have been from Gesieking that I stole the idea of playing this (and some of the other inventions....but I can't do the A minor quite at Gould's insane speed, not that I have tried since a young kid) rather quickly, indeed  Maybe it's not the most musical way to do it, but it keeps me interested when I feel like coming back to these after a little hiatus from playing.

[lettersquash]

Oh no, that "addition" definitely subtracts, to my mind. It smoothes out the parts where there's a 2-up, 1-down kind of a pattern, making those less interesting, and taking the wind out of the sails of the nice runs towards the ends of phrases, because they're now all similar runs. I'm surprised to hear Bach wrote those additions in himself. What a plonker! 

Anyway, I'm aware we may be taking the OP's thread a bit off topic. I hope some of this is useful, @billybraga, and that you're enjoying your Bach practice a bit more.

[j_tour]

Anyway, I'm aware we may be taking the OP's thread a bit off topic. I hope some of this is useful, @billybraga, and that you're enjoying your Bach practice a bit more.

Yeah, it getting maybe a bit out in left field, but then again, I do hope the OP can see some of the interest and passion one can have for even simpler pieces of Bach, regardless of one's abilities or experience. 

I'd like to think so anyway.

Although I stand by my statement that, for example, the Goldberg Aria requires artistry and fairly complete musicianship.  As does the invention, really:  maybe it should be a maxim that there are very few pieces, if any, which cannot tax the abilities of a musician to the highest degree.  No matter if he or she can play the lights out or whatever on other pieces.

Oh, and yes, I agree with you about the variant of the C -maj Invention.  Maybe one of his wives made him do it?  I do like the Gould "half variant" in the call-and-response section toward the end...keeps me from getting bored, I guess.  But, no, it just depends.  Schiff is the only recording I've heard of the full variant of the piece.  Probably for good reason, although I revere Schiff's Bach in general:  couldn't begin to guess why he used the variant for that piece. 

But in the beginning entries of the theme, it's just too much of a shame for me to be fooling around with:  the angularity is part of the fun of the piece, IMHO.

[kittenyarn]

Bach is so hard sometimes It's difficult to control two voices with one hand. Do you have any good tips at getting better at that?

[j_tour]

Bach is so hard sometimes It's difficult to control two voices with one hand. Do you have any good tips at getting better at that?

I did see your post earlier, and hesitated to reply.  Since I'm not a master....I'm pretty good, but I don't have anything to offer but anecdotal experience.

Yes, you're damned right it's "difficult to control two voices with one hand." 

Actually, it's difficult to control one voice with even two hands.

The only solution I've found is to rehearse even simpler contrapuntal pieces, with say, two voices only (but I think you're talking about pieces with three or more voices) by ear, and use utmost concentration to identify and "hear" in your mind the parts.

That is, take every moment to identify the voices and rehearse them in a purely aural fashion.  Not a bad for any music, really:  but especially in late baroque works like Bach.  From memory.  Learn it "by heart," as they used to say.  But don't be afraid of the score:  you need to read that too.

Beyond that, believe you me, I've thrown everything including the kitchen sink at Bach.

Still do.

Rewriting the scores.  Using "open scores" where each voice is notated on its own staff.  Fingering every single note. 

Creating "versions" of these pieces by cutting a, say, four voice fugue down to two voices. 

I sympathize with the difficulty, but I say you have to use every trick or technique you can. 

Cutting up photocopies of a score with a scissors.

Applying Roman Numeral Analysis.

Looking at every single edition you can find.

IME, just do every trick you can think of.  And then some.

Hey, man:  Bach is just plain difficult!  His music can be hard to play, very hard to memorize, and sometimes extremely testing of one's patience and confidence in one's musicianship.  Not like breaking out of a Jamba Juice, I can say that.

[lettersquash]

Bach is so hard sometimes It's difficult to control two voices with one hand. Do you have any good tips at getting better at that?

Hi kittenyarn, I think some of what j_tour just said might be really useful, but I don't think I would approach multi-part pieces like Bach's in that way. I should say first both that j_tour is a more accomplished pianist than I am, and I haven't played more than one part per hand so far (although many pieces have lots of notes in chords etc., I just mean where there are several distinct melodies working as counterpoint), and that different approaches will suit different people.

My main approach would be simply to work from the beginning, reading and playing all the notes as indicated in the score. This means going slowly, of course, and it also means working out the timings of each part and the fingering as well. That is a trial-and-error process, as well as excellent sight-reading practice. It may also help, of course, to play hands separate, or isolate each voice and learn that separately to help understand the piece, but the reason I favour my "vertical" method is because learning a piece is ultimately about programming the brain to do complex moves with the fingers, and when you play only part of the music, you are NOT playing the piece, so your brain is learning something else, you can play a part with fingering that will be impossible later (or, even if you stick to the correct fingering you'll need later, you'll have to figure out what it is by playing it all at once, and it will still be unnatural and awkward practised as a single line).

What goes along with this method is a need to play only short sections at once, to be careful about tiring yourself out, because it's pretty difficult at times.

There might be better methods depending on the piece, however. Something like Opening by Philip Glass, for instance, is tricky at first, because it has repeated triplets in the right hand over a straight beat in the left, so it's a bit like patting your head and rubbing your tummy in a circle! I practised just the rhythm first, ignoring what notes I was playing, until I could do that counter-rhythm. But once I've got that, I'm back to programming my brain with how to play the piece from start to finish. Here, I see little point in even playing hands separate, except perhaps as a reading exercise. It's not going to help me learn how to play the piece very much.

[lettersquash]

Another quick tip is to keep listening to other people play the piece. It can help you figure out how difficult passages go as well as familiarising you with it as a whole. If you find software or hardware that slows pieces down without making them sound too choppy, that can be a great help. I learned some tricky flute pieces with that method, just playing along to it slowed down, and I'm not trained in playing flute at all. I use a Sony program called Sound Organizer (which I think is free), which can also change the pitch independently, so it doesn't matter if the original is a bit off, or I can even transpose it on the fly! Or something similar might suit. Youtube can be slowed, but it gets a bit choppy and only has big jumps in the setting. Of course, you have to be careful if your goals include learning to read music!

[kittenyarn]

Thank you both so much for the tips I will try them out and see if it helps me!!

[lettersquash]

Thank you both so much for the tips I will try them out and see if it helps me!!

You're very welcome. It's been on my mind since that maybe I underestimate the value of hands-separate practice, particularly to figure out the best fingering and get a bit more accustomed to it. Probably the most important thing is to find what works for you, which may mean finding a few things that don't work so well first. ATB!

[aaron_banks]

Bach’s music is tricky as it is based on articulation, each voice has it’s own sound and character. To get into it legato playing is essential before starting to create articulation and phrasing (breathing). I think too many start trying to get all details in place at once.
How do you do it?

[j_tour]

Bach’s music is tricky as it is based on articulation, each voice has it’s own sound and character. To get into it legato playing is essential before starting to create articulation and phrasing (breathing). I think too many start trying to get all details in place at once.
How do you do it?

That's an excellent question.  It seems to relate to how some people suggest learning a given piece without ornamentation, then adding them in at a later point.  Learning a bit of the HobXVI:32 B-minor Haydn sonata, thanks to a discussion here which introduced me to the piece, I kind of have to do that with a lot of the (annoying!) turns in the first movement, otherwise it's kind of messing up the overall shape of the piece at the very initial stages of reading the piece fluently.

But, no, with Bach I think I always start with the kind of articulation I think the piece should sound like.

Especially for the fugues:  I kind of have one idea of the way the subject should sound, and tend to stick with that.  Similar for the ornamentation.  I don't know how I arrive at the initial conception:  probably a combination of intuition and some memory of various recordings.

I don't know if that's the best way:  I could see easily getting stuck in one habit and having to rework and revise with more difficulty as the playing of the piece evolves.

To "undo" some hasty decisions, I guess I usually go back to playing a piece more slowly and deliberately.  Which doesn't seem like a bad idea, at any stage of learning (namely, to "break it down" from time to time even if one is sure of one's ability for a given piece), but it is probably not the most efficient way of going about things.

However, thinking more about what I actually do, in the course of learning a piece of Bach in particular, I am also reading and playing each piece slightly different each time.  But it's never absent articulation, nor ornamentation (the one exception might be a really slow sarabande, or something where the time is not clear to me just from reading, without having heard a recording in probably years). 

It's always there, though, in some form, never a "neutral" kind of playing.  I just like to experiment each time and try things slightly differently.  Small things, though:  whether to lean on a bass movement or make a little arpeggiated chord outline plucked like a string.  The basic idea is pretty constant, I would say. 

[lelle]

Bach’s music is tricky as it is based on articulation, each voice has it’s own sound and character. To get into it legato playing is essential before starting to create articulation and phrasing (breathing). I think too many start trying to get all details in place at once.
How do you do it?

If I knew I wanted to do a certain articulation from the start I think I would practise it from the start. Why relearn the piece in a different way again later if I already know what I want to do? Just like I wouldn't learn every piece in forte and then add the dynamics later. You can still play legato, even if you play staccato, if you get my drift