It makes the beat sound jazzy. Usually, Hip Hop music has very simple beats, but our band modifies them so that they are complex and syncopated. This makes the music sound very cool. There are many other types of drums besides the bass, snare, and the high hat. My drum set consists of a piccolo snare, a bass drum, a high hat, a splash, thin crash and ride cymbals, two toms, and three floor toms.
Toms are useful for big rolls and bossanova beats.
Now, after reading this essay on drums, perhaps you will think differently about them when you see them being played on T.V. or at school.