Harmony, a sort-of new Broadway musical from Barry Manilow and Bruce Sussman, opens with a German singing group called the Comedian Harmonists performing at Carnegie Hall in 1933. This is framed to the audience by former group member Josef Cycowski (Chip Zien), who goes by the nickname “Rabbi”. Now an elderly man, Rabbi introduces himself, then introduces an audition scene where the younger group members are first introduced to each other. It’s a lot of introductions for the opening 10 minutes of a musical, and it won’t be the last time that Harmony mistakes throat-clearing for ceremony. Perhaps the confusion...