That really depends on why you want to rap in the first place. Are you just a fan of rap music and just want to rhyme over some beats or do you really want to pursue a career as a rap artist?
If not the latter of the two reasons for rapping your best bet would be to find some of the latest rap songs that are out at the moment then google the name of the song with "instrumental" or "type beat". _ Note - Use the FireFox web browser to search on youtube for videos to download.
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