The first time I went it was years ago when I used to do lots of swing dancing. We'd attend every concert in town, hopping to find a spot where we could dance to jazz music. JazzSí is a club owned by a great musicians school in town, and it has a sort of clandestine feel. Very small, quite dark, intimate... and they program different styles every night: some evenings there is jazz, others flamenco, others whatever else. Arrive early if you are hoping to get a sit, or you'll be standing by the bar.