Complex sentence: Bands with member (s) from the school and solo acts from the school perform at the concerts, and they usually attract about 200 people from the school, as well as people from other schools and friends/family or performers.
Split into simpler sentences: Bands with member (s) from the school and solo acts from the school perform at the concerts. They usually attract about 200 people from the within school, as well as people from other schools and friends/family or performers.