Au4 is an audio/visual creative collective formed in 2004 by brothers Ben and Aaron Wylie in Vancouver, Canada. Inspired in part by the electronica explosion of the 1990s, and landmark albums by Underworld, Massive Attack, Björk, and Nine Inch Nails, Ben and Aaron began layering and shaping musical and visual composites, accumulating a body of work that would eventually find its way onto their debut album On: Audio, and into their technically involved live show On: Visual.