This is a large orchestra, with a vast percussion section.

这是一支拥有很大的打击乐器组的大型管弦乐队。

youdao

It is a scandal that such a large town has no orchestra.

这么大一座城市，竟然没有一支管弦乐队，真是说不过去。

《牛津词典》

The orchestra are/is performing before a large audience.

管弦乐队在很多听众面前演出。

youdao

Mister Bernstein wrote other major classical works through the years for a large group of singers and an orchestra.

VOA: special.2009.08.02

For the "War Requiem, " Britten assembled a large orchestra, a smaller chamber orchestra, two organs, three vocal soloists, a chorus and a boys' choir (positioned at a distance, with a portable organ or harmonium).

WSJ: The Sounds of Sacrifice | Benjamin Britten | War Requiem | Masterpiece by Stuart Isacoff

Another built a concert hall large enough to fit a 50-member orchestra.

WSJ: Book Review: Grand Ambition