This gist contains a program that plays the music defined in tracks.
The tracks table stores nested tables — one for each concurrent track.
Each such table defines some track properties like its envelope and volume as
well as the actual notes.
A note can be represented in either of the following forms:
"C#3"means play the note of C♯3, 1 unit long.0indicates a rest (no note is played).{"C#3", 4}is just like"C#3"but 4 units long instead of the default 1.