This package provides macros for typesetting virtual keyboards
limited to two octaves for showing notes represented by a
colored circle. Optionally, the number used for pitch analysis
can be shown. It is an extension of piano.sty by Emile
Daneault, written in expl3 in answer to a couple of questions
on TeX.StackExchange:
http://tex.stackexchange.com/questions/162184/
http://tex.stackexchange.com/questions/246276/. It features
extended syntax and several options, like setting the color,
adding numbers for pitch analysis, one or two octaves, and
others.