when you're drumming and you've got a big kit, how do you know which kind of drum you should hit?  like if you have 3 cymbals and you're thinking "on this beat i want the big psppssh but on the next measure i want the medium psppssh" or can you just pick them at random and thats ok because everyone likes a little variety?
it's the same as choosing between "yep" and "yes"