Whenever we need a song or a video, the first source that strike into our minds is YouTube. YouTube is no doubt the best site for sharing videos. But sometimes instead of downloading videos, we just need the audio part of that video. In that case you can directly download YouTube videos as MP3 files using one of the following sites that allow you to convert and download YouTube videos as MP3 files.
You can also download YouTube videos in mp4 or flv format and then use some software to convert those videos to mp3 format.