For me this is the most amazing program I found when I started using Ubuntu. not only can it convert music/sound files. It can extract sound from a video file and save it as just the audio. So I can do mass batch conversions of all of my videos and have just the audio in the format I want. It also has mp3gain/replaygain which equalizes the audible volume of each track. I really like this program, I wish there was a windows version of this as well.