Learning to play a musical instrument has been shown to enhance some cognitive skills including enhanced fine-tuned auditory perception and discrimination, verbal memory, phonological skills, reading, inhibitory control, working memory, and attention [2, 1, 3, 4]. However, there is also controversial evidence of cases demonstrating inconsistent results . Furthermore, musical expertise has been associated with brain changes. For example, Thaut and colleagues found differences among prefrontal, frontal, cingulate, cerebellar, temporal, and parietal regions associated with rhythm processing in musicians and nonmusicians . Longitudinal studies are less common, but could provide unique insights into the developmental course of effects. Therefore, the current goal is to provide further longitudinal evidence and further identify the emergence of neurocognitive advantages associated with musical expertise. We are analyzing music effects in data from the Pediatric Longitudinal Imaging Neurocognition and Genetics study (PLING) of 200 5-12 year olds, featuring detailed musical assessments from the study on Studying the Influence Music Practice Has On Neurodevelopment in Youth (SIMPHONY). Child participants with musical experience have higher performance on measures of phonological awareness, lexical processing speed, reading accuracy and fluency, verbal working memory, rhythm discrimination, sensitivity to beat perception and attention skills. Initial examination of brain structure demonstrates larger bilateral subcortical volume of the cerebellum amongst participants with musical experience. Ongoing analyses are testing music associations in structural and diffusion imaging in parietal, temporal, frontal and cingulate regions, and will examine the association between growth rates of brain structure and performance on behavioral assessments over four annual time points.