Forty years ago, on July 12, 1979, what was supposed to be a wacky promotional stunt by shock-rock DJ Steve Dahl to sell tickets to a double-header White Sox baseball game at Chicago’s Comiskey Park turned ugly — when piles of vinyl records, many by artists of color, were destroyed as thousands of anti-disco rioters, 39 of whom were eventually arrested for disorderly conduct, stormed the field. Dahl has always vehemently denied that 98.7FM WLUP’s infamous “Disco Demolition Night” had any racist or homophobic undertones or intentions, arguing that “annexing this event to today’s advocacy is lazy academically and inappropriate...