You must have read my previous article on How to Download YouTube Videos in 3gp, flv and mp4 format right from the webpage.
Here is an online tool that will allow you to download YouTube Videos in mp3 format.
Instead of getting the entire video in mp4 or flv format, which consumes huge space. Mp3 is a best choice for those, who just want to listen to the music.
You can choose to download the Mp3 in High or Standard Quality.