The Museo de la Música Puertorriqueña traces the history of Puerto Rican music through instruments, memorabilia, and recordings, housed in a restored colonial building a few blocks from Plaza las Delicias. The collection covers the full arc: from pre-Columbian Taíno instruments through Spanish colonial song forms to the African-derived bomba and plena genres that are most distinctly Puerto Rican. The display of handmade cuatros — the ten-stringed guitar that is the island's national instrument — is particularly good.
The museum is modest in size but thoughtfully presented, and the audio component works: you can hear what the instruments sound like, which makes the history tangible. It pairs naturally with Casa Paoli around the corner, and together the two museums give a good grounding in the musical traditions that Ponce regards as its particular contribution to Puerto Rican culture. Allow an hour.