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I was recently handed the bottom low brass book for the Andrew Lloyd Weber Requiem. Most of the parts say Trombone IV, and a few even seem to have "Tuba" crossed out and trombone 4 written over it. However, almost the entire Requiem is in the pedal register for a bass trombone. I am thinking that, given the range and style (I don't know how much grit and growl would be appropriate for a Requiem) this would work far better on contrabass tuba.
Any TubeNetters ever play this piece?
Disclaimer:
This is a college/ community orchestra and they probably won't really care which instrument I play as long as it sounds good; I am normally asked to play tuba with that ensemble.

The big CC worked well and blended nicely for all movements at the performance last night. Just had to use the small mouthpiece to tighten / brighten and to be aware to keep a lid on the volume. The "march" section definitely sounded better on a tuba than it would have in the basement of a trombone. Even got to use my homemade 5/6-6/4 mute for 2 notes! (actually 4 notes, because of a repeat!!) I kept my gigbag next to me, turned inside out, to "catch" the mute in the 2-3 measures I had to pull it and start playing again. The performance was in a very live cathedral and a dropped mute would make quite a racket. The acoustics were absolutely marvelous for the medium sized choir - they really don't build 'em like they used to!