Sound Design Is the New Score explores film soundtrack practice that blurs the boundary between scoring and sound design, subverting long-established hierarchical relationships between dialogue, music, and sound effects. The new methods associated with this practice rely on the language and techniques of contemporary popular and art music rather than traditional Hollywood scoring and mixing practices, producing soundtracks in which it is difficult to tell the difference between score and ambient sound, where pieces of pre-existing musique concrète or electroacoustic music are merged with diegetic sound, sound effects are absorbed into the score or treated as music, and diegetic sound is treated as musique concrète. The book argues that the underlying principle that binds together all the different manifestations of this practice is a musical approach to soundtrack conceived as an integrated whole. The aesthetic concerns of this practice, demonstrated in a resistance to the familiar tropes of classical narrative and scoring, are illuminated through the concept of the aesthetics of reticence, which encourages an intellectual, affective, and sensuous engagement with film. The sensuous aspect of this practice is theorized using the concept of the erotics of art, arguing that the sensuousness of film form—its sonic and visual textures, composition, rhythm, movement, and flow—is much more complex and sophisticated than simply being an emphasis on excessive sensory stimulation facilitated by the use of digital technology or the aesthetics inspired by it.