Scotland’s innovative ‘same-personnel’ jazz quartet, blazing a trail for that rich seam of post-bop jazz, so redolent of the 50s and 60s – a time when jazz emerged from the ‘underground’ – those small, dark n’ smoky subterranean haunts of downtown New York, and into the big time when the West Coast ‘Cool’ post-Bop movement brought the music into the mainstream.