Does the processing of structural relations in music have anything in common with the syntactic processing of language? Important differences in the form, purpose, and use of syntactic structures in the two domains suggest that the answer should be "no." However, recent eventrelated brain potential (ERP) data suggest that some aspect of syntactic processing is shared between domains. These considerations lead to a novel hypothesis that linguistic and musical syntactic processing engage different cognitive operations, but rely on a common set of neural resources for processes of structural integration in working memory ("shared structural integration resource" hypothesis). This hypothesis yields a nonintuitive prediction about musical processing in aphasic persons, namely, that high-and low-comprehending agrammatic Broca's aphasics should differ in their musical syntactic processing abilities. This hypothesis suggests how comparison of linguistic and musical syntactic processing can be a useful tool for the study of processing specificity ("modularity") in cognitive neuroscience.