In music, the listener depends upon serial time to order sounds and silences so that tonal relationships can be ascertained. The purpose of this study was to investigate the effect of presentation time asynchronies on the identification of music intervals. Freshmen and graduate music majors identified music intervals on a test with the second tone of each interval delayed by 0,10,20,70,500, or 520 ms. A comparison of correct identifications for each of the six onset time delay conditions using a split-plot ANOVA resulted in a significant interaction between student class and delay condition, with significant main effects for both class and time delay conditions. Graduate students identified music intervals more accurately than freshmen students. In addition, there was a significant increase in scores across the six delay conditions for both groups. Freshmen exhibited a significant difference between the 0 ms delay condition and the 10 ms delay condition, indicating the tendency to hear physically simultaneous events as one sound. Scores for both freshmen and graduate students were significantly different between the 70 ms delay condition and the 500 ms delay condition, when the tones became successive. Successive tones were more accurately identified than tones with overlapping presentations.Measurements of perceptual onset time and resulting music label (harmonic or melodic) further showed the dissimilar experiences of the simultaneous and successive intervals. Melodic intervals were more accurately identified than harmonic presentations with most subjects separating the two tones of the interval to judge interval size. These findings suggest that training in music aural skills may influence the cognitive process used to identify the music interval.The art of music originates in the interaction of a listener with patterns of sound and silences unfolded across event time. The perception of sounds in music is based on the listener's ability to attend to selected acoustical signals and to organize the resulting sound images into perceptual units at varying levels of abstraction (Deutsch, 1982). Like all acoustic phenomena, the organization of music sounds is directly related to the physical characteristics of the signal (Balzano, 1986;Deutsch, 1982;Sloboda, 1985). These qualities of sound are frequency, time, and intensity, with which all variations in acoustical signals are possible.Discernment of multiple sound images is clearly illustrated in music perception in which a listener apprehends separate simultaneous complex tones and organizes them into meaningful relationships. Sloboda (1985) proposes, "The principal characteristic of music is that sounds stand in significant relation to one another, not in isolation" (p. 154). Groupings occur because, "elements belonging to an event are maximally similar and predictable, whereas elements belonging to different events are maximally dissimilar" (Handel, Weaver, & Lawson, 1983, p. 637).