Back in 1992, the late, great Guru laced Gang Starr B-Side DWYCK with one of the finest non sequiturs in hip-hop history: “Lemonade Was a Popular Drink and it still is.” More than twenty years later, the refreshing beverage is still a warm-weather staple—a fact which NYC spitter MadKem celebrates on his latest single. On this head-noddable cut, the Elementality Productions signee gives the enigmatic line a little context, using it as a springboard for recollections of summer months spent on the hustle…