First of all, the General MIDI specification includes 128 percussive sounds. If this were the end of it, the bafflement could be limited, but such is not the case.
Synthesizers have multiple drum kits in their mysterious chips.
Having mentioned these inhibiting threats, I would suggest that we forget about them, at least for purposes of this publication which is, after all, about making music, not about microchip technology. Thus, we will confine our comments to the drum sounds available in the General MIDI specification. Happily, sequencers provide many features that can reduce the anxiety of wannabe drummers. As a matter of fact, the task of producing and improving complex rhythms can be approached from various directions. And so it is with drum sounds.