Deezer 3

France based Deezer is the first music search engine that is undeniably legal. In their earlier incarnation as blogmusik.com, Deezer was pressured by the French government to alter their service, which they thought was skirting copyright laws. Since then, Deezer has ironed out their differences with the government by agreeing to share revenue with artists and producers.
Very fast and quality search. You can download music tracks, but in most cases, it will cost you money.