Optimo—the Scottish DJ/production duo of Keith McIvor and Jonnie Wilkes—have earned a sterling reputation as two of the world’s most discerning disco selectors. Their marathon sets are famous for their unpredictability, adventurousness, diversity, and psychedelic depth. Basically, Optimo play by their own idiosyncratic rules (e.g., early-’80s synth pop into mid-’90s minimal techno within a few tracks). Prepare yourself for six hours of incredible eclectic grooviness at this edition of the Trouble monthly. (Q, 1426 Broadway, qcapitolhill.com, 9 pm–3 am, free before 10 pm/$10 after, 21+)