They're just part of the 0.1% - and they are concert grands. Most pianos don't do this. Can I inspect one Ferrari and make the conclusion that all cars have a 600hp V12 engine? The statement I was responding to was:

"Do all the keys have the same pivot length? On an acoustic grand they don't. The long bass strings require a deeper strike point, so the overall key length increases from treble to bass."

It is stated as a rule for all pianos. But this is not true. It's only true for a small number of pianos.

Whether they're all the same length or whether some are slightly longer ... does it really matter? At all?

Not really!

I guess once the keys reach a certain length, perhaps further increases wouldn't be very noticable, or at least, not very important. And it's a simple matter of adding mass if we want to duplicate the feel as closely as possible of those huge bass keys & large hammers. Still interesting to know that the key length does vary on some pianos though.

Greg.

I recall when I asked about key length on the tuner's forum there was some discussion that when keys get long they begin to have too much flexibility, which can make them hard to play. It was a bit of a contentious issue, though, iirc. I think there's probably an optimal length.

It's another one of those moving targets because A) its subjective and B) in a complete key strike, it's one of dozens of critical measurements and ratios.

Like string length, there are limits due to material characteristics, but if you change the material, the result becomes foreign and no longer subjectively pleasing.

"when keys get long they begin to have too much flexibility, which can make them hard to play."

I can`t think of any DP where there`s a remote possiblilty o` that happening . . !

It is even very possible, that the given very long key length on a concert grands are not just for the sake of the playability at all, but as a compromise between playability and the need of having able to place the hammer where it can hit the string in an optimal position.

A given ratio of the two parts before and behind of the hammer point is regarded as optimal for sound quality and intensity.

I've seen a few, and measured my Knabe. It's 13 1/4" for key #1 (A0) and tapers down to 11 3/8" for key #88 (C8).

It's still in the extreme minority. Most are same length. The weighting of the keys and the heavier hammers account for the heavier response in bass notes. You must have inspected an unusual sequence of actions to have not seen that the vast majority that have the same key length. Or you've mostly seen very large concert grands.

James... do you know if the GF action will be on slab kawai DPs?

I do know, but cannot comment I'm afraid.

James
x

nord stage piano has very long keys.

?????

I repeat:

?????

Actually, I think Fatar's action is very small. I don't feel confortble playing it on kurzweil's boards. I think Yamaha have smaller keys than Roland (MOx8 compared to RD-300NX), but Roland doesn't have a key that can be compared to an acoustic... By the way, the Grand Piano from Anphitheater is a Kawai RX-2. I like those keys, feels just fine, and the length just pleased me, and didn't hurt my hands. Small keys sucks for playing, and doing those boring exercises my teacher ask me to do.
I'm really interested on GF action on a slab piano... If kawai do it, I'll have to wait because the price here is overpriced always... We pay at least 68% more they pay in USA(comparing to dollar).

So that's a yes then!