Peter Hollens (born March 4, 1982) is an American singer/songwriter, producer and entrepreneur. He has been involved with a cappella music since 1999 when he and Leo da Silva founded the University of Oregon's a cappella group, On The Rocks, known as the first official collegiate a cappella group in Oregon. He regularly releases new music videos to his YouTube channel. Peter Hollens is an American entrepreneur, educator best known as a classically trained vocal artist specializing in a cappella music on Youtube and Facebook. With over 5 million followers and subscribers, his content has received over a billion total views since 2011.