Complex sentence: Several of the scores require larger forces, including a large (over 100-piece) romantic-period orchestra, a mixed choir and even a boy choir, although none of the scores call for particularly immense forces compared to larger film or theater works.
Split into simpler sentences: Several of the scores require larger forces, including a large (over 100-piece) orchestra, a mixed choir and even a boy choir. However, none of the scores call for particularly immense forces compared to larger film or theater works.