I already did the piano... for me with a minor degree in music, it was easy. And yes, it's strictly sound. I knew right away to
start with G and then go to B flat
. But these puzzles that just use sound must be awful for non-musical people.
To try to explain better...
the piano scale starts with C and goes up by one white key to D, E, F, G, A, B and then to C. So, first find "middle C" by going to the middle of the keys and locate the white key before the two black ones. Then go up to find G... That's your starting key for the sequence. The second key is B flat or the third of the black keys after G.
You should be able to go from there.
Don't know if this helps, GreyFuss!