Both sets of the twins would be drumline, I think. Starscream? ...I'm tempted to say trumpet. Soundwave? Err... French horn? I dunno know. Your right, Blaster needs to be drumline as well... Geez, we have a huge drumline section at this point.

Tuba's... Maybe Megatron and Optimus Prime? Tubas are the base of the rest of the band (it's the pyramid!) And Skyfire... As sad as it is, I kinda wanna give him a piccolo. But I doubt that would work, so a flute or clarinet?

What about the minibots? Cliffjumper, Huffer, Bumblebee, Powerglide, Beachcomber, Gears... Oh, and what about Prowl? *has a vision of a guard-member Prowl*