This essay explores the durational gaze of the spectator and the audience, and the importance of a precisely measured or chronometric rehearsal process in realizing a rarely performed experimental Modernist stage composition. 'Der Gelbe Klang' (The Yellow Sound) was Wassily Kandinsky's only published stage composition, featured in Kandinsky and Franz Marc's Der Blaue Reiter (The Blue Rider Almanac) in 1912. Rarely performed but academically scrutinized, the script, such as it is, provides little clue to its performative duration. Eighteen pages long, consisting of a mixture of written prose and illustrations of medieval woodcuts, Egyptian ideograms, and Bavarian stained glass windows, the text is divided into one prologue and six pictures to be realized upon a stage. The essay draws on the Practice as Research production co-directed by D'Arcy and Hand and performed at CCI Atrium Cardiff and Tate Modern in November 2011.