Understanding the relationship between music and language has implications for people with language disorders, such as aphasia. The Shared Syntactic Integration Resource Hypothesis (SSIRH; Patel, 2003) proposes that syntactic processing of language and music draws on distinct networks for words and chords but relies on partially shared resources for integrating those elements into the context of a sentence or musical phrase. One prediction of the SSIRH is that people with aphasia (PWA) with syntactic comprehension deficits should also present with musical syntactic processing deficits. The present study aims to determine if PWA present with abnormal P600 event-related potential (ERP) responses to violations of linguistic and musical syntax. A secondary aim is to determine if there is a relationship between musical training and the brain’s response in both domains. Neurophysiological responses to linguistic and musical syntactic violations were investigated in seven PWA and 14 healthy controls. Both groups presented with a significant P600 ERP response to syntactic violations in both domains. Comparing the PWA to the healthy controls, we found that patients presented with a reduced-amplitude P600 response to linguistic, but not musical, violations, suggesting intact online processing of musical syntax. Additionally, the PWA also presented with larger frontal positivities in response to violations in both domains. For both groups, musical training significantly positively correlated with P600 amplitude in posterior regions in response to violations in language and music. This suggests that musical training may impact syntactic processing of language, even after stroke.