YouTube introduced its Audio Library on September 25th 2013. When you are uploading the videos in YouTube, tired searching the best music? Now YouTube makes it simple.
Currently YouTube Audio Library provides 150 royalty free instrumental tracks and you can use the same for free forever. Great thing is you can download the music as 320 Kbps MP3 files.
Link on http://www.youtube.com/audiolibrary?feature=blog to have access to the Audio Library.
Also if you want to add music to your videos in YouTube. First navigate to your page Dashboard and then under “Creation Tools” you can find the “Audio Library”.