Casa de la Trova, is a club dedicated to more traditional type of Cuban music. Nice open air courtyard, room to dance. Groups change every hour or so, and ALL of them will try to sell you a CD. It was the best music venue, I'd visited in Trinidad. You will not hear Celia Cruz there, but maybe this song.
Every tourist group ends up there eventually, but the music is pretty good, the Mojito is strong and genuine. Drinks are 2.5 CUC, which is cheap by Toronto standards, but not by Cuban. There were several Trinidadians sitting there. (they pay in pesos)