WIP, just press green flag.
Song is a bit of Yoshinao Nakada's Song of Twilight, all graphics by me. The 4 panels will show graphs of transposition, musical tension etc. The 3 lists btl, fullnbt and fullntp define the song; fullnbt and fullntp are semicolon-separated lists; fullnbt defines how long note n is held in; fullntp defines what note n is; btl defines how long to wait until the next group of notes is played. I had to construct it by hand.
