Rip music from YouTube.Visithttp://convert2mp3.net/en/to find a simple interface for pulling audio files from YouTube videos and saving them as MP3s. This is a simple way to get songs you want quickly, though it has some drawbacks: the quality of your MP3 files will be fairly low, and the quality of the sound can't be improved if it was already poor on the YouTube video itself. Additionally, any empty space or non-musical parts of a video will also be ripped. However, the process is very easy: just paste the URL of the video you want into the text box and click ?Convert Video.
This site and others like it exist in a legal limbo of sorts. The service itself may or may not be entirely legal, but your chances of getting in trouble from using it are slim to none.
For those of you saying that it's illegal, It's not explicitly illegal and it's not explicitly legal. Like a lot of copyrighted materials and digital property, there is a big grey area. In music downloading especially. If you download a song off of you tube, technically you are not breaking copyright. Another example of this is downloading a movie vs. streaming it from a website other than the ones licensed to use it. If you download it, its illegal because you don't have the rights to it. But, if you just watch it online, you're not technically doing anything illegal.
better method is using something like SMLoader and ripping straight from Deezer, supports FLAC and 320Kbps, and comes with metadata/album art use soulseek for more obscure stuff