Timbral similarities among wind instrument duos were studied. Flute, oboe, E𝄬 alto saxophone, B𝄬> clarinet, and Bl> trumpet instrumentalists performed in all possible duo pairings (dyads). Source material included B𝄬4 unisons, unison melody, major thirds, and harmonized melody. Nonunison combinations had each instrument of the pair as the soprano, creating a total of six contexts. Music major and nonmusic major subjects rated the similarity of all possible pairs of dyads in each of the six contexts. Classical multidimensional scaling (MDS) was performed; contexts were treated as " subjects" in an individual differences scaling (INDSCAL) analysis of composite data. The resulting spaces had two stable, interpretable dimensions. From verbal attribute rating experiments ( Kendall & Carterette, in preparation, a), these were identified as " nasal" vs. " not nasal," and " rich" vs. " brilliant." A third dimension was interpreted as "simple" vs. "complex."Extrema in the space were associated with three of the five instruments: Trumpet (brilliant), saxophone (rich), and oboe ( nasal). Data that were amalgamated over contexts and plotted in two dimensions yielded a circumplicial configuration. Implications for orchestration are discussed and a theoretical model of timbre combinations and groupings is presented.