Hey hey, it’s The Monkees on Mad Men.
Music: The song at the end of the episode is “Porpoise Song (Theme from “Head”) by The Monkees
Significance: It’s about questioning your place in the world. Something they all do on this series. Especially this season.
Factoid: Written by Carole King and Gerry Goffin. Also notably used in the movie Vanilla Sky.