Ansel Collins is one of the most prolific keyboardists in all of reggae—the list of albums he has contributed to is positively staggering. After hitting the charts in the early ’70s with “Double Barrel,” “Monkey Spanner” and “Stalag 17,” he settled in with the Revolutionaries band, featuring the indomitable Sly Dunbar and Robbie Shakespeare. These recordings all date back to that time (1979, to be exact) and were made at Kingston’s Channel One Studio. Half are dubs or instrumentals and half feature vocals, often by Collins himself (not always a good thing). Essentially, these are well-produced examples of some of reggae’s best players in peak form at the height of the music’s international success. But one of the most compelling reasons to pick up this set is the final track, “Ease Up The Pressure.” Featuring the roots singer Tony Tuff, it is mixed in “Jamaican stereo,” which means the vocals are all on one channel and the music is on the other, so that you can create your own “version” with the balance knob. Get busy!