This introduction presents an overview of the concepts discussed in the subsequent chapters of this book. The book explores the mechanisms in Howard Hawks’s films by which an outsider is incorporated into a cohesive group by musical means. It looks at Hawks’s use of music on a more intimate scale. Hawks often treats dialogue as if it were music, casting his actors in such a way that their voices complement each other. The book examines those of Hawks’s films in which music is marked as “music,” rather than as a diegetic dramatic communication tool. By the 1940s the musical language of underscore was fully established and most films featured it to some extent, sometimes approaching the “saturation score” with music playing throughout. In Hawks’s world, most music is communication and most communication is musical, his films a compendium of the many ways in which people use music to communicate.