Complex sentence: Oxford Music Online, "The Mountain Sylph" Gilbert and Sullivan's comic opera "Iolanthe" (1882) parodies the theme of a fairy who, for the love of a mortal, is banished from fairy society with the consent of her Queen.
Split into simpler sentences: Oxford Music Online, "The Mountain Sylph" Gilbert and Sullivan's comic opera "Iolanthe" (1882) parodies themes from "The Mountain Sylph". In that work, for the love of a mortal, the fairy Iolanthe is banished from fairy society with the consent of her Queen.