Piano World Home Page Forums Our Most Popular Forums Piano Forum When was the key size standardized?

I found this article which talks about the standard size of a modern keyboard https://en.wikipedia.org/wiki/Musical_keyboard but I've been having a hard time finding out *when* that standard was set.

My teachers turn of the 20th century Steinway has slightly narrower keys than my brand new Yamaha, and having played a bunch of new-ish pianos (no more than 20 years old) they were all obviously exactly the same size (though the shape varies, especially of the black keys.)

I'm also wondering if this has anything to do with Rachmoninoff's famous enormous reach and seemingly impossible chords. Is it possible on today's pianos he would be off a note?

The width of the keys has been approximately the same since before Rachmaninoff was born.

Do you have a source for this info? As I mentioned, my teacher's Steinway from the early 1900's has narrower keys than my Yamaha (and also narrower than his newer Steinway he has upstairs out of his studio, we actually measured the two keyboards out of curiosity and they are definitely different.)

What was the difference in total length of the keyboards measured?

Regards,

The very bottom of this interesting article has two tables that show the historic size of a piano octave. Looks like most pianos have fallen within a very small range since the 1700s, but there were and continue to be some outliers. So I guess there is no actual standard, just common practice.

... and no discussion of this topic is complete without a nod to the varying-sized Steinbuhler keyboards.

Larry.

Just over an inch for the whole keyboard, so a bit more than 52mm for a 1mm variation discussed in the Wikipedia article. However, less than if it was a 7/8 scale.

I do not think I have seen keyboards on Steinways that vary by as much of an inch in width over 88 keys. They are all about 48 inches wide, which is the same as others.

Standard scale length is 48 3/8" wide (1228 mm) and has been in Steinways for quite a long time. There were a few different widths of keys supplied to Steinway, the narrowest being 1219 mm (48"), and those were supplied by Pratt Reed (1960's - early 1980's when Steinway acquired Kluge and went back to 1228 mm). Those at the turn of the 20th century varied even less, no more than 1/4" over the entire keyboard.

I'm not sure what you've encountered. 7/8 or 3/4 specialty keyboards are far narrower than you've described. Certainly we see other variations in older keyboards due to repairs, replacement of keytops or sharps that shrink individual keys, but not the overall spacing.

I'm quickly becoming familiar with all of these numbers since we acquired Roseland Piano Co. We make custom keysets on original frames for rebuilders. Before we acquired Roseland, we used their services for 20 years, and we got a lot of feedback from customers and artists to know how important a couple of millimeters can be to the feel. An inch would seem like a mile.

Interesting, the piano was rebuilt in the 80's so maybe something happened?

My understanding is that it was Liszt that required the changes in compass and key size. He also had very large hands. He toured frequently and visited many piano factories and had tremendous input.

I have read that Liszt could barely reach a 9th without rolling his hand.

There are pianos that are easier to play with small hands because there is less vertical key travel. My grand is this way. The difference to my upright is quite noticeable. I have not measured the keys, but there might be a slight difference in width too. For me even a half cm would make a big difference because that is what is missing from my strech for a proper octave...

Edit: I just measured the octave on my U1 and my 50's Bluthner grand. They are almost exactly the same, yet I can play with much less tension on the grand. This must be due to touch and key travel and the keytop material, which is not slippery on the grand.

Just sometime after WW2 NY Steinway head scale dropped from 48 3/8" to 48". It remained that way until they switched to Kluge keys around 1984. Steinway later bought the Kluge company.

Aeolian American actions, including Masoin & Hamlin also were 48" head scale. Whereas the original M&H headscale was something around 48 5/16".

1920 Steinway O 48-1/4"
1923 Mason & Hamlin A 48-1/2"

Hi Sam,

So pleased you took over Roseland. We have done in house keyboards, as well as having them made by sub-contractors. Maybe we should talk.

You mentioned a 3/4 sized keyboard??? I have never seen one. That seems just too small to be able to play. If you have a video of one being played or photo of one I would love to see it.

We have done some 11/12 and 7/8 keyboards for clients. Here is one we did that was fitted with a new keyset by David Steinbuhler. I apologize for the tuning in advance:





Cheers!

Most old American uprights were 48" head scale. Companies such as Kimball, Baldwin, Sohmer also 48"

This is why the vast trove of old ivory keytops from so many pianos don't fit the pianos we restore such as Steinway, M&H.

1911 Mason & Hamlin A 48-1/2"
1948 Steinway D 48"

Bechstein E 1907? and M 1930? 48"
Steinway 1928 48-3/8"

Steinway L and B, 1927 and 29 respectively, 48-3/8", like the one just above, which is a D, I forgot to mention.