Maybe you should learn was music is, because rap is every bit as musical as The Rolling Stones. The format is different, but it consists of rhythms, tones, progressions; tensions and releases. Sure, it is more lyric-oriented, but it's still music.
Having said that, I can't stand rap that is too lyric-oriented. It has to have some instrumental focus and depth to it (ie Dr. Dre), which would be hip-hop. If its just a bunch of samples or 4 notes on loop then I would rather stab my ears with knitting needles.