Audacity

This open source tool could process and edit audio file format into WAV, MP3, OggVorbis and AIFF or record audio file through soundcard. Such as to digitalized your analog music disc.

There so much effect available to edit audio. Such as, you can delete noise, add echo, change the rythme and tempo seperately, or playback song from last to beginning.

Audacity could handle until 16 audio track. So you could mix many sound. Using integrated equalizer, you can change frequency, such as to louder backing vocal or add bass effect.

Website | Direct Download (1.2.6 version)