This is John Chambers' music directory. Most of the music here is in the abc notation, which you can find out about by visiting the abc home page. If you find a tar.gz file here, it probably contains more or less the same thing as the abc subdirectory.

Some of the things here:
directory description
abc my abc tune archive
book assorted historical music collections that have been transcribed to ABC
humor musical humor
ndx my abc tune finder's index files