Though 1986’s Sands of Time marked the end of the road for The S.O.S. Band, the group quit at their absolute peak. Working in collaboration with Jimmy Jam and Terry Lewis, they'd perfected an idealized blend of sophisticated long-form R&B. The songs on Sands of Time have it all: incredibly dark and patient grooves, stratums of texture, and of course, ingratiating hooks, most of which are delivered by Mary Davis, the group’s magnetic frontwoman. Beyond the masterful production and arrangements of “Even When You Sleep,” “Borrowed Love,” and “Nothing but the Best,” these songs are remarkable for their refusal to compromise to the sunny conventions of '80s pop. The music is catchy and danceable, true; it's also moody and aggressive and even a little elusive. (Jimmy Jam and Terry Lewis devised a much more pop-friendly iteration of this formula for Janet Jackson.) Anyone who doubts this is some of the richest and most advanced pop music of the '80s has only to listen to “The Finest,” a contender for the most magnificent of the group’s many singles.