Arthur Sullivan had high aspirations for himself as a composer of symphonies and grand opera, but his fate will be linked forever to that of his witty librettist, William Gilbert. Gilbert and Sullivan, one of the most successful musical teams in history, created comic works that are hard to classify. They're not exactly classical--though they parody the operettas of Offenbach and Strauss and are usually sung more in a classical than a musical theater style--and they have speaking parts. Add some very British slapstick, and they can seem a little like Monty Python meets opera buffa. First produced in 1878, H.M.S. Pinafore was the team's first huge hit. It was performed around the globe and made them both rich and famous. It's also one of their best, taking on love across the barriers of rank and money and poking fun at the British navy. In the main plot the captain's beautiful daughter is engaged to a high-ranking member of the navy, but she pines for a lowly sailor, who adores her--though of course neither of them knows how the other feels. There are also subplots and lots of choruses and dance numbers. Evanston's Light Opera Works has produced reliably professional music theater since 1981, when it opened with a performance of H.M.S. Pinafore. This cast includes soprano Sharon Quattrin, who's sung with Music of the Baroque and Concertante di Chicago, and baritone Robert Heitzinger, a Northwestern University faculty member who's sung with Chicago Opera Theater and the Lyric. The orchestra will be conducted by Peter Lipari. Sun 12/26, 2 PM, Cahn Auditorium, Northwestern University, 600 Emerson, Evanston, 847-869-6300, $27-$59. See also Monday, Tuesday, Wednesday, Thursday.