Discotheques come and go quickly in Ayacucho [1], but Puka’s (Cusco 246, evenings only) is for the moment packed on weekends.
The best peña is Los Balcones (Asamblea 187, 2nd Fl.), which is a disco Tuesday–Thursday and a peña on Fridays and Saturdays.
Los Warpas (Mariscal Cáceres 1033, tel. 066/31-5559) has a good peña on Friday and Saturday nights (don’t eat here, though).
A good bar is Magia Negra (9 de Diciembre 293, tel. 066/960-5644, 7 p.m. onward Tues.–Sun.), and an evenings-only pool hall operates on the corner of Bellido and Garcilazo.
A small cinema on the Plaza de Armas, near the corner of Cusco and Asamblea, shows movies and documentaries sporadically.
Links:
[1] http://www.moon.com/destinations/peru/central-highlands/ayacucho