The Sunset Playhouse’s seasonal bon bon, “Hollywood Holidays,” is a compendium of movie tunes sung individually by four young performers. Yes, there is “White Christmas,” “Jingle Bell Rock” and “Santa Baby,” as well as a lovely rendition of “Have Yourself A Merry Little Christmas” bravely encountered by 17-year-old Laura Mesrobian. But there are also some less familiar numbers, including “All I Want for Christmas” from the movie Love Actually, well sung by the more experienced stentorian voice of Doug Clemons. And there are glitzier seasonal songs originating in the Grinch and Muppets films. Performing with requisite gusto are Cynthia Cobb, Brian Myers and Bob Hirschi, the narrator, belting out more show-tune numbers such as “Let it Snow.” Unfortunately the show was only scheduled for two days, but the full house Monday night seemed completely engaged by a concert that barely lasted 90 minutes.