VIDEO: Jason Alexander Explains How He Once Tee'd Off Stephen Sondheim

On last night's LATE SHOW, Jason Alexander, STAR of Broadway's THE PORTUGUESE KID, recalled starring in Stephen Sondheim's MERRILY WE ROLL ALONG and explained how he really ticked off the legendary composer. Later, Alexander confesses that he started acting with the role of Hamlet in mind, not George Costanza, and he and Colbert perform an impromptu duet from MAN OF LA MANCHA. Watch the appearance below!

Performances began on September 19th for Manhattan Theatre Club's world premiere of The Portuguese Kid, a new play written and directed by Tony, Pulitzer Prize, and Academy Award winner John Patrick Shanley. Opening night is set for Tuesday, October 24 at MTC at New York City Center - Stage I

The cast of The Portuguese Kid stars Tony Award winner Jason Alexander(six-time Emmy Award nominee for "Seinfeld," Jerome Robbins' Broadway, Merrily We Roll Along), Pico Alexander (Punk Rock, What I Did Last Summer, Home Again), Aimee Carrero ("Young & Hungry," "Elena of Avalor," and the upcoming "American Horror Story"), three-time Tony Award nominee Sherie Rene Scott (The Front Page, Whorl Inside a Loop, Everyday Rapture), and two-time Tony nominee and Drama Desk Award winner Mary Testa (The Government Inspector, First Daughter Suite, Queen of the Mist).

In Providence, Rhode Island, habitually widowed Atalanta (Sherie Rene Scott) pays a visit to her second-rate lawyer Barry Dragonetti (Jason Alexander). Intending to settle her latest husband's affairs, this larger-than-life Greek tightwad quickly becomes a nightmare for her cheesy, self-aggrandizing attorney. Add Barry's impossible Croatian mother (Mary Testa), a dash of current politics and a couple of opportunistic young lovers, and you have in hand a recipe for comic combustion.

Photo: Scott Kowalchyk/CBS