Several people have said that RAP is not music. I had a music theory professor with a PhD who defined music as simply: noise within structure. Rap may well be non-melodic. Much of the Avant-garde music of the 20th century, Schoenberg, Glass etc., isn't very melodic, but is generally considered to be music. You can hate it if you want. I hate most of what comes out of Nashville these days but I wouldn't say "That's not music".