The purpose of this study was to determine the effect of instrumental timbre preference and instrumental timbre on the error detection skills of undergraduate conducting students. The study sought to answer two specific questions: Is timbre preference, as determined by Gordon's (1984) <u>Instrumental Timbre Preference Test</u> (ITPT), a factor in the ability of undergraduate conducting students to detect errors in pitch in short melodies while viewing the score? Is the ability of undergraduate conducting students to detect pitch errors in melodic passages influenced by the instrumental timbres of the band ensemble? To answer these two questions, Gordon's ITPT and the researcher developed <u>Test of Timbre Effect</u> (TTE) were administered to 147 undergraduate conducting students in 11 colleges and universities in Virginia, North Carolina, and Tennessee. The TTE was designed to consist of seven different subtests, each intended to be administered to a different sample of homogeneous undergraduate conducting students. Each subtest consisted of 14 randomized test items, including two melodies designated as "target melodies" that differed only in timbre across the subtests. The effect of timbre preference, timbre, and the interaction of the two independent variables was determined by a 2 x 7 analysis of covariance (ANCOVA) of each target melody. Further analysis was conducted using a two-way multivariate analysis of covariance (MANCOVA). Results indicated that timbre preference, timbre, and the interaction of timbre preference and timbre did not have an effect on the ability of undergraduate conducting students to detect pitch errors in short melodic passages. / Ed. D.