Are You With It? manages quite a feat: overcoming a ridiculous plot and a mediocre score to emerge as an infectious and utterly appealing musical. Mind you, quite a few musicals of the period have plots and premises that strain credulity, but With It is really just plain silly. Fortunately, the screenplay itself is engaging enough that most viewers will buy into the premise; it's not great writing, but it has a certain flair and a certain charm to it. More importantly, its flair and charm play to the very considerable strengths of star Donald O'Connor, allowing him to use his peculiar charm to extremely good advantage. Like Danny Kaye, who also carried a number of rather silly pictures, O'Connor skillfully uses With It as a showcase for his comedic and musical talents. That the Sidney Miller-Inez James score doesn't really provide him with any great numbers doesn't matter; he and co-star Olga San Juan take the serviceable "What Do I Have to Do (to Make You Love Me?)" and make it seem like a much better song. And O'Connormakes a memorable and very nifty routine out of a musical excursion that links mathematics to tap dancing. The star also milks every laugh -- whether a verbal joke or a physical situation -- for everything it's worth. He gets good support not only from San Juan but from Martha Stewart, whose "Daddy, Surprise Me" goes over very well, and from Lew Parker, whose deft comic performance gives O'Connor a run for the money. Lightweight it may be, but Are You with It? is well worth seeing for its star.