Nu stiu clar dar iti pot da niste site-uri:
Http://mp3cut.net/
http://www.looplabs.com/
http://www.forwindows.net/program-de-modificat-muzica/
http://www.forwindows.net/program-de-modificat-melodii-tutorial/
http://audacity.googlecode.com/files/audacity-win-unicode-1.3.13.exe