title track
From Longman Dictionary of Contemporary Englishtitle trackˈtitle track noun [countable] the song or piece of music on an album (=collection of songs or pieces of music) that has the same name as the whole albumExamples from the Corpustitle track• The singer was chuffed when her album title track Proud was chosen as Labour's election theme song.• While often meandering, the trip consistently yields epiphanies, as in the lengthy, two-part title track.• That is a bluesy harmonica on the title track.• The title track is a sunny romp about gawd knows what.