Has anyone ever played this piece in concert? My conservatory's Contemporary Music Ensemble that I'm in is starting rehearsals next week. Is there any advice in particular someone can give who has performed it before?

Learn l’appel interstellaire and convince the conductor to make it a trombone solo instead.

Wow, what a cool piece! I have not performed it, but would love to have the opportunity. When I was in school, our contemporary ensembles mostly did smaller chamber works. You should feel very fortunate to be at a school that is tackling a full orchestra Messian work.

In this day and age, we have so many tools available to help us learn literature much faster. There is a recording of it on YouTube that shows the orchestral score. I would spend hours watching and listening to that recording. It’s like having a clinic on the piece. Fortunately, Messian wrote it in small, digestible fragments. That should make it easier to take notes on what instruments play the different parts when you have rests.