There is an engaging song in West Side Story in which the young heroine, Maria, blurts out the joy of being in love:

           I feel pretty, oh, so pretty,
           That the city should give me its key.
           A committee
           Should be organized to honor me….

Besides being pleasant, the lyric is a model of craftsmanship. It states a simple emotion, clearly and with precision, and yet it is not dry. It has a girlish lilt, a touch of humor, and, as all good lyrics should, an element of surprise—in this case a triple, mainly internal rhyme.

Nevertheless the man who wrote it, Stephen Sondheim, wanted to remove the song from West Side Story during its tryout. He felt that the lyric, though technically expert, was wrong for Maria: she would not use a three-syllable word or express herself in such a complex pattern. Sondheim was overruled by...