Staff writer Tom Laskin interviews Rockin' John McDonald, the 45-year-old postal worker and encyclopedic host of WORT-FM's popular vintage-rock show, "I Like it Like That." Rock 'n' roll grabbed McDonald early: "The first track I heard was by Bill Haley, 'Crazy, Man, Crazy.' Then I heard 'Shake, Rattle and Roll.' I bugged my parents and said, 'I gotta buy that record.'" His collection now fills three walls' worth of custom-built floor-to-ceiling record shelves, Laskin reports, and he draws on it for his show's playlists, ranging from Duane Eddy and Buddy Holly to the Blasters, the Rousers and Killdozer by way of the Beatles and Led Zeppelin. "I don't like the term 'nostalgia,'" he says, "because I think it's still good music." McDonald continues to anchor "I Like it Like That" from 6 to 8 p.m. Saturdays on WORT.