Sondheim was an unknown and untested man of the professional theatre when Arthur Laurents suggested him as a possible collaborator on West Side Story. Sondheim had hoped to bring his music and lyrics to the Broadway stage, but Saturday Night (1955, with book by Julius and Philip Epstein) stalled after its main producer, Lemuel Ayers, died in August 1955. With this project stalled, Sondheim heeded the recommendation from his mentor, Oscar Hammerstein II, to seize the opportunity to work with Laurents, Bernstein, and Jerome Robbins. This article attempts to explain the opinions of Laurents and others in the mid-1950s that Sondheim’s lyrics were brilliant but his music left them cold. Sampling his early lyrics and Sondheim’s recordings of himself singing his songs, I show how his music might be considered challenging but would nevertheless propel his words and musical theatre in general to a greater understanding of music’s dramatic possibilities.