He steps in to play "My Girl" at the 20th anniversary party/rave for Alan (William Russ) and Amy Matthews (Betsy Randle) when the real band gets accidentally sent away. Gordy was best man at their wedding. He forms a quick impromptu band with Jedediah Lawrence (Peter Tork), and Reg Fairfield (Davy Jones). 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!
Weirdly, Dolenz had another, earlier musical role on the same show, as a member of Alan's old band The Tongues. But there his character was named Norm, and even more confusingly, there was another member of the Tongues named Gordy, but that was played by Rick Nielsen of Cheap Trick.
Gordy didn't get a last name.