Riddell is one of the prominent figures in the history of Australian Computer Music. Born in Melbourne, Riddell Australia studied Music and Computer Science at La Trobe University in Australia and holds a PhD in composition from Princeton University in the USA where he studied with Paul Lansky and Jim Randall. He was also a postdoctoral fellow at La Trobe University (1995-96) and President of the Australasian Computer Music Association (1994-96). Currently, he lectures in Sound Art and Physical Computing in the School of Art and is a visiting Fellow in the College of Engineering and Computer Science at the Australian National University.