Great bar on Obispo, one of the main thoroughfares in Habana Vieja (old town), great all-girl band in mid-late afternoons with a relaxing atmosphere, in the same street as the Hotel Ambos Mundos which contains Hemingway's room (no. 52). Also, there is an excellent bar in Calle O'Reilly, nearby - don't worry, it's not an Irish bar!
Calle Obispo 316, esquina de Calle Aguiar, Habana Vieja;
tel: 7-862-9870