Complex sentence: New England Conservatory's Preparatory School is an open enrollment institution for pre-college students that offers music classes and private instruction for young musicians, and fosters over 20 small and large ensembles.
Split into simpler sentences: New England Conservatory's Preparatory School is an open enrollment institution for pre-college students. The Preparatory school offers music classes and private instruction for young musicians, and fosters over 20 small and large ensembles.