Music Search Engine crawler

I need music search engine to be developed. - None of the songs are going to be hosted on our server. - Very powerful crawler needs to be developed so it can crawl other website and create indexed pages for music download. - Similar websites are: [login to view URL], [login to view URL] but we need better crawler to have maximum amount of international songs. - Website already has developed social networking section programmed in asp.net in c# with ms sql as database. So, it has to be programmed in the same way so it could be connected. - Visitors should be able to click download and it should download automatic without directing them to any external website. - Visitors should be able to create playlists with those songs.