Thespis (partially found score to Gilbert and Sullivan opera; 1871)
Thespis was the very first collaboration between legendary Opera duo, W.S. Gilbert and Arthur Sullivan. The opera ran for 63 performances and closed down the next year, considered a successful run at the time.
The opera survives only in the form of a libretto, allowing details of the plot and dialogue to be known. The plot involved an acting troupe traveling to Greece and switching places with the gods on Mt. Olympus. Proving to be quite the inept rulers, a bunch of cosmic hilarity ensues. According to reviews, the audience was left roaring with laughter throughout the opera's running time.
Most of the opera's music is now completely lost. No sheet music was widely distributed and no sound recordings survive. There are a few exceptions, though. Two of the opera's songs, "Climbing Over Rocky Mountain" (a chorus with solos) and "Little Maid of Arcadee" are known to exist. "Climbing Over Rocky Mountain" got a modest sheet music release while "Little Maid of Arcadee" was featured in a future Sullivan production. A short ballet from the production was discovered in the 1990s and had a couple of performances, none of which were recorded.
The missing music from this opera has left Gilbert and Sullivan fans high and dry. Isaac Asimov—famous science fiction writer and lifelong G&S devotee—wrote a short story, "Fair Exchange?", about a man who travels back in time to "rescue" the opera from being lost (with unintended consequences). Many recreation efforts have been attempted, but the music is still yet to surface in any form.