system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: what's the deal with rap music? What makes rap music, and what's the criteria for "good" rap music?

I listen to rap from time to time, and do enjoy it, but I don't exactly understand why it's "music." Although there are instrumentals, there are no pitches to the lyrics. Is it just supposed to be a sort of vocal percussion? And when music critics (or you) evaluate this kind of music, what makes it good?
gpt
There are things like:

* Clever lyrics and humor
* Rapping before or behind the beat
* How smoothly the lyrics come out
* The timbre of the guys voice
* The quality of the beats and other instrumentation

Rhythm is very important but there are simple melodies in the verses if you listen carefully.