He based his first book, "Opera as Drama" (1956), on a series of essays written for "The Hudson Review" beginning in 1948. Published in several languages and multiple editions, "Opera as Drama" expresses Kerman's view that an opera's story is key and provides the basis for the structuring of both the librettist's text (which expresses the narrative) and the composer's music (which expresses the emotions in the story). For Kerman, the value of an opera as drama is undermined when there is a perceived disconnection between text and music. Among the operas Kerman discussed in the book was Puccini's "Tosca" which he controversially described as a "shabby little shocker." (Kerman's assessment echoed George Bernard Shaw's earlier description of Sardou's play "La Tosca" on which the opera was based as an "empty-headed turnip ghost of a cheap shocker.")