The father of main character Topanga Lawrence (Danielle Fishel), he steps in to play "My Girl" at the 20th anniversary party/rave for Alan (William Russ) and Amy Matthews (Betsy Randle). The real band was sent away, so Jedediah (Peter Tork), Alan's friend Gordy (Micky Dolenz) and refined British freeloader Reginald Fairfield (Davy Jones) form a quick impromptu band to sing Alan and Amy's wedding song. This is 3/4ths of The Monkees! Even better, after they play, they're approached by "The Manager" played by Dave Madden, who played manager Reuben Kinkaid on The Partridge Family!
More bizarrely, Tork only played the character twice, with actor/musician Michael McKean of Spinal Tap playing the role in a 1999 episode, and then actor Mark Harelik.