The ‘temp track’, a temporary mock-up of a film's soundtrack, is assembled from pre-existing music prior to the real, commissioned score being composed. An integral element of the post-production process of American feature films, it survives only in its role for audience previews. Constructed by a music editor, in most cases, it is a blueprint of a film's soundtrack – a musical topography of score, songs, culture and codes in which a balance must obtain between the director's vision, the music's function, underlying requirements of genre, and the spectator's perception. This article demonstrates that the temp track informs compositional practices and the final score, and makes the argument that textual analysis would benefit from the recognition of the role of production practices. Drawing on published sources and interviews with practitioners, this article provides historical context and musical detail, and shows how productive analysis can be when it draws on practitioners' insights as well as textual analysis. Film score analysis must not begin and end with the finished film score but must utilise a more eclectic methodology which takes into account the production process. Film score analysis should reflect the constitutive nature of film and film music.