As it happened, the highlight of Three Men and a Baby. . . Grand! was a provided by pianist John Boswell when he had the audience shout out song titles. He wrote them on a list, then performed a medley on the spot. I know this trick happens in places like The Big Bang and Jive and Wail all the time, but it still impresses me. How does a musician do that? Most important, how can so many different forms of music be woven into a coherent whole? In Boswell's case, it must be genetic because he told us his dad could do it too.