The current study investigated the relationship between planning processes and feedback monitoring during music performance, a complex task in which performers prepare upcoming events while monitoring their sensory outcomes. Theories of action planning in auditory‐motor production tasks propose that the planning of future events co‐occurs with the perception of auditory feedback. This study investigated the neural correlates of planning and feedback monitoring by manipulating the contents of auditory feedback during music performance. Pianists memorized and performed melodies at a cued tempo in a synchronization‐continuation task while the EEG was recorded. During performance, auditory feedback associated with single melody tones was occasionally substituted with tones corresponding to future (next), present (current), or past (previous) melody tones. Only future‐oriented altered feedback disrupted behavior: Future‐oriented feedback caused pianists to slow down on the subsequent tone more than past‐oriented feedback, and amplitudes of the auditory N1 potential elicited by the tone immediately following the altered feedback were larger for future‐oriented than for past‐oriented or noncontextual (unrelated) altered feedback; larger N1 amplitudes were associated with greater slowing following altered feedback in the future condition only. Feedback‐related negativities were elicited in all altered feedback conditions. In sum, behavioral and neural evidence suggests that future‐oriented feedback disrupts performance more than past‐oriented feedback, consistent with planning theories that posit similarity‐based interference between feedback and planning contents. Neural sensory processing of auditory feedback, reflected in the N1 ERP, may serve as a marker for temporal disruption caused by altered auditory feedback in auditory‐motor production tasks.