Glaser was a member of the mainstage cast of "The Second City" during the mid-1990s, performing alongside future "Saturday Night Live" head writer Adam McKay and cast member Rachel Dratch, as well as future "Mr. Show" and "30 Rock" cast member Scott Adsit. In Second City's award-winning revue "Pinata Full of Bees," which was directed by Tom Gianas, Glaser sang about the importance of not betraying a friendship by pretending not to have legs in order to play in a wheelchair basketball league. He also provided musical accompaniment for the show's climax by drumming in a demonic pig mask, and appeared onstage throughout the show to pass judgement on audience members for laughing at jokes he considered socially irresponsible.