John Kirby led a most unusual group during the height of the big-band era, a sextet comprised of trumpeter Charlie Shavers, clarinetist Buster Bailey, altoist Russell Procope, pianist Billy Kyle, drummer O'Neil Spencer, and his own bass. Although Shavers and Bailey could be quite extroverted, the tightly arranged ensembles tended to be very cool-toned and introverted yet virtuosic. Kirby, originally a tuba player, switched to bass in 1930 when he joined Fletcher Henderson's Orchestra. He was one of the better bassists of the '30s, playing with Henderson (1930-1933 and 1935-193...