This Spanish DJ performs with ’80s portable audio machines and cassettes. Why? Because he says the sound is better. Look closely at this DJ playing music at a friend’s wedding party in Huesca, in Spain’s Aragon region, and you’ll see something curious. He has all the moves of a music-mixing machine: hunched with headphones, finding the next track to play to the dancing crowd. But something is missing: There are no turntables, no vinyl in sight.