Son jarocho is the folk music of Veracruz state, built on harp, jaranas (small guitars), the large requinto guitar, and the zapateado — a percussive footwork style danced on a wooden platform called a tarima. It is a music of African, indigenous, and Spanish elements that arrived in the Gulf port and mixed over centuries, and it sounds like nowhere else in Mexico. Most evenings, groups of musicians and dancers set up in or near the Plaza de Armas, and the performances draw impromptu audiences of locals and visitors.
La Bamba is the most famous son jarocho — most people know it as a 1950s rock and roll song, but it is originally a traditional piece from Veracruz, and hearing it played on harp and jarana in the plaza where it came from is a different experience entirely. If you're in Veracruz during a festival — particularly Carnival — the son jarocho is everywhere. On an ordinary evening, the plaza performances are informal and free, and one of the most authentic things about the city.