Before moving on to the American Battleground finals or, just possibly, the World DMC Championships to be held in France this August, one skilled DJ has to survive the Northern California Regional Competition to be held right here in Sacramento on July 1. What’s the DMC you ask? That’s the Disco Mixing Club, a worldwide organization that promotes the art of turntable mixing and has absolutely nothing to do with the polyester-clad Adonis, Tony Manero. Now in its 21st year, the competition not only promotes the work of the world’s most talented and creative DJs, but also provides a forum for spectators to find out firsthand how such artists keep the mixing arts vital. This year’s event will take place at 7 p.m. at the Collings Teen Center, 1541 Merkeley Avenue in West Sacramento. Tickets are $10 and are available at a number of local record stores, including area Dimple stores and The Beat.