Complex sentence: The opera and Meyerbeer are both referenced in the musical "Phantom of the Opera": "Lot 664-a human skull, from this house's 1831 production of" Robert le diable "by Meyerbeer".
Split into simpler sentences: The opera and Meyerbeer are both referenced in the musical Phantom of the Opera. "lot 664 a human skull, from this houses 1831 production of Robert Le Diable by Meyerbeer".