by Phil Harris, although conductor Mahlon Merrick actually led the band). The second half of the show would be devoted to a comedy sketch. Jack might leave the studio and go home to handle some problem (e.g. getting Carmichael to take his medicine). Or there would be a miniplay (e.g. "Buck Benny Rides Again," or a murder mystery starring Jack as Police Captain O'Benny), or a satire of a current movie (e.g. "Snow White and the Seven Gangsters"). In some episodes, Jack closed the show with brief instructions to his band leader ("Play, Phil."), and the band would play a final musical number, as Don Wilson did a final commercial. Over the years, The Jack Benny Program evolved into the modern domestic situation comedy form, crafting particular situations and scenarios from the fictionalized life of Jack Benny, the radio star. The sitcom shows often took place in Jack's house in Beverly Hills, with the story revolving around some aspect of Benny's life. For example, an entire show might be devoted to Jack taking a violin lesson, instructed by his harried violin teacher, Professor LeBlanc (played by Mel Blanc). Common situations included hosting parties, income-tax time, nights on the town, "backstage" interactions between Jack and his cast during show rehearsals at the radio studio, contract negotiations, traveling in the Maxwell, or traveling by train or plane to and from Jack's many personal appearances throughout the country (hence the "Train leaving on track five" running gag). The sitcom shows usually opened with Jack handling some common domestic task (e.g. Spring cleaning or organizing the pantry), with help from Rochester. As the show progressed, Jack would receive visits or phone calls from Mary Livingstone, Phil Harris or Bob Crosby (who replaced Harris as the radio show's "band leader" in 1952), and Dennis Day. Following an exchange with Day, Benny would order him to "rehearse" a song ("Let's hear the song that you're going to sing on my show tomorrow night."), and Dennis would sing a number. Don Wilson would bring the Sportsmen Quartet over to Jack's house, to sing a new commercial for the sponsor, Lucky Strike Cigarettes, to Benny's consternation. Later in the show, Jack might step out to handle some common errand, such as going to the dentist, or visiting a store to buy a new suit, where the dentist or store clerk would inevitably turn out to be Frank Nelson.