Boy meets girl served for a half-century as sufficient plot for virtually every Broadway musical. Then came a couple of decades of boy meets exotic locale, boy meets social dilemma, boy meets religious destiny, and boy meets his literary creator -- not to mention similarly unromantic encounters among personified animals and steam engines. Even musicals that focused on love tended to be wistful and full of woe, as if passion must always be a snare and delusion or a doom-struck mistake.
This season, however, Broadway has three new musical productions that reclaim the giddy simplicity of the past. Only one, the...