RJD2 (born Ramble John "RJ" Krohn; 27 May 1976) is an American music producer and musician. RJD2 was born in Eugene, Oregon and raised in Columbus, Ohio. He currently resides in Philadelphia, Pennsylvania. He was signed to the Definitive Jux label where he released two largely instrumental hip-hop albums and has produced tracks for many prominent rappers. However, he has now left Definitive Jux and has signed with XL Recordings. His 2007 album, The Third Hand, is a striking departure from his usual style and features Rjd2 singing and playing instruments on nearly every track.
In 2009, Rjd2 established his own label, RJ’s Electrical Connections and reissued three early records as well as a box set. Rjd2's new full length More Is Than Isn't was released on October 8, 2013 on his new label, which is distributed by The Orchard.
Rjd2's work has been used heavily in media and advertisement, particularly the singles "The Horror" and "Ghostwriter". Since 2007, Rjd2's "A Beautiful Mine" has been the opening theme for AMC's Mad Men.