Castro and colleagues make a decisive distinction between general familiarity and personal familiarity. A popular song may be culturally recognisable, whereas personally familiar music is grounded in direct experience and can be attached to people, places, objects and specific spatiotemporal-emotional contexts. Using fMRI with composers, the study compares participants’ own compositions, favourite music by others and unfamiliar music, followed by personally familiar and unfamiliar names. Music carrying autobiographical content recruits a fronto-parietal network including dorsolateral prefrontal, supramarginal/angular and precuneus regions; favourite music engages reward and emotion networks, while self-composed music more strongly recruits self-referential and visuomotor processes. The methodological operation is unusually precise because familiarity, autobiographical relevance and self-reference are experimentally differentiated rather than merged. The study bridges neuroscience and autobiographical-memory theory by demonstrating that apparently equivalent states of “knowing” music can have different cerebral architectures depending on how the musical object entered the listener’s life.