The National have unveiled a new song titled “Sunshine On My Back.” The song, which can now be download via iTunes or streamed on Spotify, features singer-songwriter Sharon Van Etten on vocals. The song was recorded during the sessions for the band’s most recent album, 2013’s Trouble Will Find Me. The band released the b-side to celebrate the release of the documentary Mistaken For Strangers for rental and purchase on VHX.