Who can possibly dislike "The Music Man"? Meredith Willson's monster 1957 hit musical (later a huge success as a movie) is a squeaky-clean masterpiece, an amazing feat of creativity by Willson, who wrote the book, music and lyrics. Director-choreographer Susan Stroman's rousing revival does brilliant justice to this all-American classic that takes place, as one character puts it, in the "hailstone-and sarsaparilla belt" that the Iowa-born Willson knew so well. If you wanted to get highfalutin, you could say that the character of Harold Hill (Craig Bierko), who comes to River City to fleece the rubes with his phony scheme to sell them instruments for a boys' band, is a variation on the …