Claim: Romance with a Double Bass revolves around Smychkov (Cleese), a bassist, who shows up too early for the ball of a beautiful princess, who, meanwhile, has gone fishing at the lake.
Evidence: Smychkov (Cleese), a bassist, shows up too early for the ball of a beautiful princess, and decides to spend his extra time skinny dipping in the nearby lake. The princess (Booth), meanwhile, has gone fishing at the lake, and later decides to go skinny dipping as well.