Complex sentence: The composer Cesare Pugni arranged a new version of Delibes'music--he expanded the opening waltz in accordance with Petipa's new staging, and also composed new variations for the principal ballerinas.
Split into simpler sentences: The composer Cesare Pugni arranged a new version of Delibes'music. Pugni also expanded the music for the opening waltz in accordance with Petipa's new staging, and also composed new variations for the principal ballerinas.