LONDON — In early 1988, Danny Rampling, a D.J., asked George Georgiou to design a flier for his club night Shoom in a south London fitness center. “They used to clear all the equipment away and put a sound system and a D.J. in the corner,” Mr. Georgiou said. “It was extremely loud, very crowded, this awful strawberry smoke everywhere, strobe lights going off all the time.” He was given one conditi