I was singing with the Palestrina Choir from Christendom under the direction of Dr. P, and it consisted of everyone who had ever sung with that choir (so it was bigger than it ever was in real life). We received an invitation to sing at the Roman Colosseum with another choir, I think the Vatican Choir. Anyway, so for some reason, when we arrived at Rome, the director of the Vatican choir took one look at me and said, "I didn't want EVERYone."
On a side note, having never been to the real Colosseum, my mind associated the exterior with the stage. Each person had their own individual window, and they were all stacked on top of each other, so there were no rows of people standing behind each other.
Anyway, everyone else took their places in the Colosseum-windows including Dr. P, who sang in my place when he wasn't directing. Out of a massive choir, I could easily see Brittany and Beth, as they had ground and second row positions, and when I looked around, everyone else had blended into the structure well. When they began singing, the sound was an absolutely glorious one, but one dominated by the Palestrina Chorale. While the director was busy patting himself on the back for such a fantastic idea of blending his choir with Dr. Poterack's, all the while suggesting to his own choir that they paled in comparison to Christendom's.
So, after listening to the whole practice, I had to evacuate, because it was a sold-out house, to standing-room only, and even that was filled to overflowing. The choir was supposed to wait in their positions for the audience to come in (which they did in droves).
Since there was nothing for me to do except either listen to the concert from outside or go exploring, I did the latter, since I had heard the practice. Unfortunately for both of us, I don't remember this part of the dream.