Re: Piano keyboard
It would be tough to play if all 12 were side by side. This way you can reach all of the keys with your hand in one place, like a typewriter on computer keyboard or telephone. Saves space and makes them all easier to use. I'm sure the key of C had something to do with the arrangement, and seeing the black makes it easier to distinguish when looking for them quickly. Imagine a guitar with one long string capable of all tones but you couldn't reach it. Also helps to play chords. I have small hands but can reach a C to C octave (piano) but not if 12 keys were side by side.
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