Playing a musical instrument requires efficient auditory and motor processing. Fast feed forward and feedback connections that link the acoustic target to the corresponding motor programs need to be established during years of practice. The aim of our study is to provide a detailed description of cortical structures that participate in this audio-motor coordination network in professional pianists and non-musicians. In order to map these interacting areas using functional magnetic resonance imaging (fMRI), we considered cortical areas that are concurrently activated during silent piano performance and motionless listening to piano sound. Furthermore we investigated to what extent interactions between the auditory and the motor modality happen involuntarily. We observed a network of predominantly secondary and higher order areas belonging to the auditory and motor modality. The extent of activity was clearly increased by imagination of the absent modality. However, this network did neither comprise primary auditory nor primary motor areas in any condition. Activity in the lateral dorsal premotor cortex (PMd) and the pre-supplementary motor cortex (preSMA) was significantly increased for pianists. Our data imply an intermodal transformation network of auditory and motor areas which is subject to a certain degree of plasticity by means of intensive training.