Broadway vet and self-confessed showtune obsessive Seth Rudetsky launched the Turtle Creek Chorale’s 34th (!) season last night at the Meyerson with his one-man act that put to shame folks who consider themselves knowledgable theater queens.

Rudetsky’s shtick — an hour-long monologue with some piano playing and lots of audio clips — is a deconstruction of what makes great singers great, and sometime terrible. (Or, in Rudetsky’s words, “Amahhhzing!!!!” and “Uh….mahzing.”) He parses vibrato versus sliding off-key, belting a song (“head voice”) versus playing it close to the chest (Carly Simon is his favorite exponent of that), riffing for showiness versus expert control. And he did so in such a speedy Long Island accent, it was sometimes difficult to catch it all. (Don Jones, the TCC’s sign interpreter for 20 years, got a shout-out from Rudetsky for his ability to keep up.) But over and over, his encyclopedic knowledge and sense of the fabulous won over the audience.

He also set up Act 2 of the concert, in which the TCC performed with its Partners in Harmony, songs from Broadway, starting with a piece from Les Miserables and the most appropriate song from the operetta The Most Happy Fella, “Big D,” before seguing into Doris Day, a piece from Ragtime (which the chorale performed with Uptown Players earlier this year) and Sweeney Todd (which the chorale will perform with Uptown Players next year). It was a song-filled evening, and a nice kick-off for the storied men’s chorus’ next season.