Integration of auditory and visual information is important to both language and music. In the linguistic domain, audiovisual integration alters event-related potentials (ERPs) at early stages of processing (the mismatch negativity (MMN)) as well as later stages (P300(Andres et al., 2011)). However, the role of experience in audiovisual integration is unclear, as reading experience is generally confounded with developmental stage. Here we tested whether audiovisual integration of music appears similar to reading, and how musical experience altered integration. We compared brain responses in musicians and non-musicians on an auditory pitch-interval oddball task that evoked the MMN and P300, while manipulating whether visual pitch-interval information was congruent or incongruent with the auditory information. We predicted that the MMN and P300 would be largest when both auditory and visual stimuli deviated, because audiovisual integration would increase the neural response when the deviants were congruent. The results indicated that scalp topography differed between musicians and non-musicians for both the MMN and P300 response to deviants. Interestingly, musicians’ musical training modulated integration of congruent deviants at both early and late stages of processing. We propose that early in the processing stream, visual information may guide interpretation of auditory information, leading to a larger MMN when auditory and visual information mismatch. At later attentional stages, integration of the auditory and visual stimuli leads to a larger P300 amplitude. Thus, experience with musical visual notation shapes the way the brain integrates abstract sound-symbol pairings, suggesting that musicians can indeed inform us about the role of experience in audiovisual integration.