Audacity is an Open Source audio application designed to be a
full-featured, yet easy to use multi-track recording and editing suite.Audacity
can record live audio through a microphone, mixer, digitize recordings
from other media, and capture streaming audio. Audacity can record,
import and export, modify quality, has a ton of built-in effects,
analyze capabilities, plug-ins and just so much more we're just
scratching the surface.
It supports almost all of the popular
audio formats out there including WAV, AIFF, Ogg Vorbis, FLAC, MP3, and
FFmpeg-compatible files. Oddly enough, the one format it does not
support is M4a which is popular with Apple and iTunes. If your music
library has a lot of songs you downloaded from iTunes, you're going to
need to download a converter first.