# Note layouts for an alternative piano keyboard

Lately I have been working on rearranging keys of a piano keyboard, as you can see on my song “Galactic Overload”.

The note layout for that piece is the following one:

I call it “555” because it contains 3 groups of 5 keys each.

The tuning system is a 15 note version of
Carlos Alpha (see my article Alpha Compressed Octave).
The numbers on the white keys show their round distance, in cents, from what I consider the root key. The tuning system repeats every 1169.925 cents.

Is that one the best note layout for Carlos Alpha on an alternative piano keyboard?

I started investigating trying to follow the same line of thought that brought to the creation of the
The piano keyboard is not an isomorphic one, so there must be a privileged set of keys (the white ones) representing the main “key” of the system. The (visual) disadvantage of this note layout is its symmetry with 3 equal groups of 5 notes each.
Keeping the same ratio of 6 black for 9 white keys I came up with 2 alternatives:

this one (named “357” ) does not include ratio 3:2 with the root note on a white key

this one (named “375” ) seems better than the 2 previous ones because is more “diatonic” (white keys include a nice approximation of ratio 5:4, ratio 3:2 and the interval close to 6:5, 312 cents, is on a black key).
These 2 layouts share the same mechanical problem: there are no 2 white keys of an Halberstadt keyboard that fit as the first 2 keys of this configuration because these is never, on a regular keyboard, a single black key separating 2 white ones. To fix this problem you need, somehow, to sand those keys to make them thinner, as I will demonstrate on an
upcoming article.

Another layout using the same number of black and white keys would be:

this one (named “771” ) has a main mechanical disadvantage: that full white key (with no indentations) appears on Halberstadt keyboard only once (it is always the top key). If I needed 4 or 5 of those keys I would have to dismember as many keyboards to get them! Of course I could use other, indented, keys but it would be an ugly solution.
Besides that, 2 adjacent small steps (78 cents), compared to the large ones (156 cents), on white keys do not make any sense to me.

Other solutions?
What about a layout using 7 black and 8 white keys?

Compared to the previous ones, this one needs a lot of black keys:
a 61 keys keyboard would require 28 black and 33 white ones.
For comparison, a 61 keys Halberstadt keyboard has 25 black and 36 white ones and those configurations with 6 black and 9 white keys need (for a 61 keys keyboard) 24 of the former and 37 of the latter ones.

If, instead, we consider Carlos Alpha as the ninth root of ratio 3:2, 2 more note layouts come to mind:

this one suffers from the same visual problem as the one called ”555” because of its symmetry. A 61 keys keyboard, using this layout, would require 20 black and 41 white ones.

The other one is:

A 61 keys keyboard, using this layout, would require 27 black and 34 white ones.

After all this thinking I decided to go for the “375” note layout.

To be
continued...