Complex sentence: Catalani fainted from stage fright at the end of the first act, and as a result some of her music in the second act had to be omitted; furthermore place in the finale of the opera was taken by another singer.
Split into simpler sentences: Catalani fainted from stage fright at the end of the first act, and as a result some of her music in the second act had to be omitted. Her place in the finale of the opera was taken by another singer.