These files are .lsdsng tunes.

They are meant to be played on a gameboy using a tracker called "Little sound DJ".
http://www.littlesounddj.com/lsd/

You can merge several .lsdsng into one .sav using this tool
http://code.google.com/p/lsdmanager/

Some of the tunes were recorded and included in these albums :
http://dataglitch.bandcamp.com/album/world-1-vineyard
http://dataglitch.bandcamp.com/album/world-2-factory
http://dataglitch.bandcamp.com/album/world-3-greenhouse
http://dataglitch.bandcamp.com/album/world-4-castle