La La Land's clunky dancing

For all their crazy chemistry, the stars of Hollywood's new musical, La La Land, don't actually sing or dance all that well. Somewhat surprisingly, this actually makes the movie work. Musicals are famously one of the most challenging art forms, not just because of their built-in artificiality, but because they require that a dramatist, choreographer, composer, and lyricist collaborate, and that every singer also be a decent actor and dancer. Yet for a movie in dialogue not just with movies but w...