"Six Degrees of Inner Turbulence" is the sixth song and title track on the album of the same name, written and performed by progressive metal/rock band Dream Theater. Though the song is essentially broken up into eight movements on separate tracks, it lasts 42 minutes in full and takes up the entire second CD of the album. The song was conceived when keyboardist Jordan Rudess wrote what would become the "Overture" section, and the band took various melodies and ideas contained within it and expanded them into segments of the complete piece. The song explores the stories of six individuals suffering from various mental illnesses. Particularly represented are bipolar disorder, post-traumatic stress disorder, schizophrenia, post-partum depression, autism, and dissociative identity disorder.