A drum set needs drum cases, so I am assuming you're making something that is temporary. Does he want the sides of the drums protected? You need a circle of fabric for the top plus fabric to go around the sides. I suggest elastic at the bottom to keep it on the drums not drawstrings. For protection it all probably needs to be heavily padded. Covering the top takes less fabric than covering top and sides. You could also fasten the sides with velcro and not use elastic. Does he stack his drums when he moves them? Does he already have sacks for his high hats,drum sticks and foot pedals? Good luck to you.