Wild flights of melodic imagination, held steady by irrepressible grooves—these are among the characteristics of salsa, the hot that has filled dance floors for decades. Salsa de la Bahia is a compilation of recordings by San Francisco bands, most of them recent and originally released on indie labels and little heard outside the Bay area. The two-disc set is an impressive document of a particular music scene and bears witness to the variety that can be found within the genre. The performances are tops.