Stephen Sondheim has made it clear that he considers himself a ""playwright in song."" How he arrived at this unique appellation is the subject of ""How Sondheim Found His Sound"" - an absorbing study of the influences on Sondheim's work not normally associated with musical composition, such as theater and film. The book also traces the development of Sondheim's musical language, showing how that language, forged before Sondheim had a successful Broadway show, appears throughout his career.