keyboard spacing

[reredouble]

Piano black keys have different spaces between them:

Easiest to see if you look at the part of the D key that's between the black keys. 
Compare to the G and A keys.
Pretty subtle, but if you stick your finger in there and wiggle, you can feel the space is largest on the D.

I found a website of a guy who has noticed this.  He had a demo at the Los Angeles Musician's Union, but didn't leave the piano there.

I'm not a classical player, and didn't have time to play much.  But one of the Mozart examples on the website made sense to me (my hands are small) and the other didn't affect me (it was for big hands.)

Now I look at all my pianos and, sure enough, they all have a big D (and E).

Does anybody know why this is?
Wierd!
https://mozarttechnique.com/

[j_menz]

[le_poete_mourant]

LOL

[outin]

I just measured my D, G and A and they are exactly the same: 1,2 mm. Is my piano defected?

[le_poete_mourant]

I just measured my D, G and A and they are exactly the same: 1,2 mm. Is my piano defected?

Clearly you've been ripped off. Take it back to your piano dealer immediately and demand that they either refund your money or replace your keyboard with a keyboard of the proper specifications.

[outin]

I just measured my D, G and A and they are exactly the same: 1,2 mm. Is my piano defected?

That was of course supposed to be 1,2 cm...would need to have pretty slim fingers to go between the black keys otherwise

[lhorwinkle]

It's the same with digital pianos.

You'd expect C and F to be identical. But they're not.
You'd expect E and B to be identical. But they're not.
You'd expect D, G, and A to be identical. But they're not.

I've not done any measurements on my Yamaha, but ... when ordering replacement keys, the manufacturer had different part numbers for C, D, E, F, G, A, B.

I presume that the difference is related to the varying gap between the black keys.

[iansinclair]

It's the same with digital pianos.

You'd expect C and F to be identical. But they're not.
You'd expect E and B to be identical. But they're not.
You'd expect D, G, and A to be identical. But they're not.

I've not done any measurements on my Yamaha, but ... when ordering replacement keys, the manufacturer had different part numbers for C, D, E, F, G, A, B.

I presume that the difference is related to the varying gap between the black keys.

Um.  Well, remotely possible.  But at least on my pianos (all acoustic, sorry), I observe two things: first, that the spacing between keys is absolutely uniform -- that is, the space between any two adjacent black keys is the same as any other, and all white keys are exactly the same width.  The other thing which one observes, though, is that the string spacing is also absolutely even.  Ah... here we have why the different keys have different part numbers!  The hammers for all 12 keys of an octave must be evenly spaced -- but the keys are not.  The white keys (all the same width) have the black keys "squeezed" between them.  Therefore to get even spacing, a C action will be a different shape from a D (it has a B -- white -- on one side, and a C# -- black -- on the other).  And so on.

[le_poete_mourant]

This has got to be one of the stupidest, most pointless debates I've ever seen on this forum. I will resist the urge to say "size doesn't matter," and simply point out that I fail to see how this topic in any way contributes to anything useful in the real world. Geez.

[pjaul]

On my piano the skinny part of the b and the skinny part of the e are about .1 mm different which actually had me considering taking a different fingering for the recapitulation than in the exposition for a mozart concerto.  I have wondered if they are supposed to be the same size.

[withindale]

Piano black keys have different spaces between them: because you can't move Ab sideways. Have a look at the cut outs in the white keys.

Here's a shot of a Kawai K8 keyboard:

[outin]

OK, after a more accurate measuring, there is actually about 0,5mm difference between certain keys on my Yamaha as well...

[hfmadopter]

Piano black keys have different spaces between them: because you can't move Ab sideways. Have a look at the cut outs in the white keys.

Here's a shot of a Kawai K8 keyboard:

Hmm, never noticed it but on my Kawai digital all G's are tighter than the rest of the keys ( to fit a finger between G flat and G sharp). That's the tightest fit on the keyboard all the way through. On my Henry F Miller grand it isn't as tight except for G below middle C, that is equal to all G's on the Kawai. The grand feels just a bit more spacious otherwise. I have not measured though.

Interesting, not going to be life changing but interesting !