Before Ozzy had his own prime-time television show, before Elvis joined the army, there was a time when rock ’n’ roll was still evil—and the radio waves were a battleground for the souls of America’s youth. On one side were parents; on the other side was Alan Freed. During the course of his legendary career, the pioneering disc jockey established more than his share of rock milestones—not all of them glamorous—while serving up the rotten music of sin and sexuality to innocent teenagers. In 1952, he hosted the first-ever rock concert and even popularized the term “rock ’n’ roll.” But Freed also ushered in the career-ending scandal when he was busted for Payola and pioneered the depressing celebrity fade-out—blackballed by the networks, he drank himself to death in Palm Springs. However, like many a tragic rocker to come, Freed’s undoing was teendom’s gain. His legacy lives on when Floyd Mutrux’s 1978 dramatized Freed biopic American Hot Wax shows at 7 p.m. at the Library of Congress’ Pickford Theater, 101 Independence Ave. SE. Free. (202) 707-5677. (Aaron Leitko)