While most of Trinidad's old-town streets are coffin-quiet after dark, several joints bop with live Cuban music nightly. One of the best spots to sit outside, have a mojito or beer, and hear good traditional bands is the small plaza midway up the steps leading to the Casa de la Música. The dance floor is usually a good mix of polished, semiprofessional locals and foreigners whose hips are somewhat less smoothly oiled. The steps are often overflowing with people checking out some free music under the stars from 8:30pm until midnight. Inside the Casa de la Música, a more raucous environment prevails until the wee hours for a cover charge of CUC$1. Just around the corner on Fernando H. Echerri, Palenque de los Congos Reales has an open-air stage where you can sometimes catch Grupo Folclórico performing Afro-Cuban music and dance (performances aren't regularly scheduled). At other times, there may be a standard trova or son group playing. It's open daily from 10am to 1am, and until 10pm on Saturday. The Casa de la Trova, Fernando H. Echerri 29, a block east of the Plaza Mayor, is the traditional spot to listen to Cuban bands and try out a few dance steps; it's open daily from 10am to 1am, and there's a cover charge of CUC$1. A similar spot is Casa Fisher (ARTex), on Lino Pérez 306 between José Martí and Francisco Cadahía, but the scene here can be hit-or-miss.
The Ruinas del Teatro Brunet, Maceo between Zerquera and Simón Bolívar, puts on a nightly Afro-Cuban cabaret-style show in the spacious courtyard of the ruins of the city's first theater. Another bar set in a delightful open-air courtyard in the ostensible ruins of a colonial home, the Ruinas de Segarte, Jesús Menéndez s/n between Callejón Gado and Juan Manuel Marquéz, is an intimate affair and open from 10:30am to 1:30am daily, and also has live music most nights.
La Canchánchara, Rubén Martínez Villena at Pablo P. Girón, sometimes has a few musicians assembled, but it's mostly just a little open-air courtyard bar in an atmospheric colonial house, a good place to kick back in old wooden chairs and have a mojito or the eponymous house drink, made with aguardiente (firewater), lime, and honey. It's open daily from 8:30am to 2am (but no food is served).
Club Amigos de la Parranda, Rubén Martínez Villena 59 (Patio del Templo de Santeria Yemaya) is home to a group of older guys who play traditional music and accept suggestions from the public. Donations are, obviously, gratefully received. It's open daily 10am-midnight.
One of the most unusual nightspots in Cuba has to be the dance club carved out of a deep two-level cave, Discoteca Ayala, also called La Cueva (tel. 41/99-6133). Though it can be deadly hot, and the kitsch factor is undeniable, it's still pretty cool to dance to blasting disco-salsa tunes as colored lights bounce off stalactites. The crowd on weekends is largely Cuban. Now if they could only install air-conditioning to go with the lights and sound system, nocturnal spelunking would be even more appetizing. To get there, you can either walk up a path leading directly behind the cathedral, off Juan Manuel Márquez, or take the longer route from Hotel Las Cuevas (it's not actually on the premises of the hotel, though it's under the same management). It's open Tuesday to Sunday 10pm to 2am (later Fri-Sat); admission is CUC$3.