My friend told me about an app which is Free Music Monster (http://itunes.apple.com/us/app/free-music-monster-for-youtube/id585483537?mt=8)
I downloaded and have been using it for 1 days. It's quite good. They have rankings, recommendations and top music, free totally. But most of users I don't know.
Are you using this app? Please follow me to share music taste! :-D
Check ou my profile at: http://freemusicmonster.com/profile/1000012548/music.html
Hope to tlak with you soon! <3