The world of DJing has evolved from vinyl, to CDs, to hardware controllers used to run files via a laptop, USB stick or tablet. The pro DJ software used here falls into three main camps: Pioneer rekordbox, Serato and TRAKTOR, run from WIRED’s iPad Air 2 and Apple MacBook Pro 13-inch to ensure ample processing power. Each item on test offers auto-sync, full pitch control, cue points...