Peter James Hollens 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. With over 9+ million followers and over 3 million subscribers, his content has received over a billion total views since 2011.