This paper reports a preliminary study based on the theoretical assumption that continuous closed-loop audio-motor control could be disadvantageous for pianists. It is argued that the functional relationship between the intracerebral electrical activations in the auditory and premotor cortex should be rhythmically decreased and increased. To test this hypothesis, intracerebral electrical activations for the auditory and premotor cortex were estimated using scalp EEG and standardized low-resolution electrical tomography (sLORETA). The extracted times series were subjected to a Granger causality analysis, revealing a causal relationship from the auditory cortex to the premotor cortex that was considerably stronger during piano playing and weaker during rest. Importantly, this relationship varied rhythmically during the course of piano playing, with lags (obtained with cross-correlations) between 666 ms and 820 milliseconds. This study thus delivers evidence that the functional coupling between the auditory and premotor cortex varies during piano playing.