Mr. Kotter, move over. This year’s Oscar host, Steve Martin, is giving lessons in classic comedy on a new radio show that premiered last weekend over Minnesota Public Radio. Martin, 56, is due to host the majority of shows in the 39-week season of “Comedy College,” analyzing classic sketches from such deft monologists as Victor Borge, Mort Sahl, Bob Newhart, Lenny Bruce. The half-hour show is airing on Saturdays on Minnesota Public Radio and over the Web site of Comedy College. (Last Saturday’s topic was Bill Cosby. “He’s one of the funniest storytellers since Mark Twain,” Martin said of the Cos, 64.) In other media news, the dubious distinction of the first casualty of the new TV season goes to “Danny,” a sitcom starring lanky 44-year-old character actor Daniel Stern (“City Slickers”) as a divorced dad, CBS announced. The network axed the show after only two broadcasts and will replace it this Friday with a rerun of its Monday night sitcom “Yes, Dear.” No permanent replacement has been announced. Originally titled “American Wreck,” “Danny” followed “The Ellen Show,” but both shows have struggled in their timeslots. CBS was hoping to use the twice-delayed Emmy Awards, which Ellen DeGeneres was scheduled to host, as a platform to promote the new comedies.