Nils Lofgren is an American rock musician. He released the albums Acoustic Live, Back It Up!! Live... An Authorised Bootleg, and Nils Lofgren. Lofgren has performed and recorded with Grin, Crazy Horse, and Bruce Springsteen & the E Street Band. His most popular songs include Keith Don't Go and Black Books. Lofgren appears in the Apple Original Film Bruce Springsteen's Letter To You, the documentary Bruce Springsteen: Wings for Wheels - The Making of Born to Run, and the documentary The Session Man.