From a study by Pantev C, Lappe C, Herholz SC, and Trainor L:
Learning to play a musical instrument requires complex multimodal skills involving simultaneous perception of several sensory modalities: auditory, visual, and somatosensory as well as the motor system. Musical training thus provides an adequate neuroscientific model to study multimodal integration and plasticity in musical training. The aim of this study was to investigate the impact of short-term uni- and multimodal musical training on auditory-somatosensory integration and plasticity. Two groups of nonmusicians were musically trained. The first group (sensorimotor-auditory group, SA) learned to play a musical sequence on the piano, whereas the second one (auditory group, A) actively listened to and made judgments about the correctness of the music. The training-induced cortical plasticity effect was assessed by recording musically elicited mismatch negativity (MMN) from magnetoencephalographic (MEG) measurements before and after training. The SA group showed significant enlargement of MMN after training compared to the A group, reflecting greater enhancement of musical representations in auditory cortex after sensorimotor-auditory training compared to mere auditory training. This study demonstrates that the sensorimotor and auditory systems integrate and that this multimodal training causes cortical reorganizational changes in the auditory cortex over and above the changes introduced by auditory training alone [emphasis added].
It’s not that music appreciation isn’t a fine thing. But if you’re looking to improve your brain organization, then you need to learn to play an instrument. What’s important is learning to not only gain both physical control of both gross and fine motor movements, but translate written symbols into meaningful action. However, not all music teachers are equally good, and it’s important to pick the right teacher. Otherwise, you’re just hanging around in the vicinity of an instrument.