Audacity

Audacity is an open source audio editing and voice editing program. It allows users to record and edit audio files, including microphone audio and audio from Internet streaming. It allows you to import and export various digital audio formats, including WAV, AIFF, MP3, Ogg Vorbis and FLAC. Users can edit files using effects and filter tools, including equalizers, volume correction, transitions, holes and reverse. Audacity also allows users to create multi-channel audio and synchronize audio with video.

Audacity - With this program, you can easily handle recording live music, convert various audio recordings to digital form, edit MP3, WAV and OGG, cut, copy and mix sounds, add effects and much more.

Here you will find a guide to controlling the program and editing music: Sound Editing - A Manual.