It can be unlocked even if you haven't started the quest by entering the cave just east of Juna, the snake associated with both the quest Tears of Guthix and the Tears of Guthix Distraction and Diversion (the cave is empty with no dangers present). The track will then appear in green on the music list, and the 'unlock hint' will improperly read: "This track was unlocked during The Chosen Commander".