Free Wheeling is a piece of software created by coder and musician J.P. Mercury specifically in order to help him compose music live in the fashion which works for him.
That is so cool I can barely stand it.
He’s got a couple songs on the project page, which I really like, and a link to a bunch of his music, creative-commons licensed and housed on Archive.org.
I am in awe.
Alas, I am not on board, cause I couldn’t get it to compile on OS X. It wanted “libfreetype6,” whatever that is.