Bob Dylan, 'Don't Think Twice, It's Alright' (Season 1, Episode 13)
"Nostalgia — it's delicate, but potent." Don's pitch for Kodak's slide projector is a stunner, using snapshots of the Drapers (their wedding day, Betty pregnant, the kids as babies) to sell the idea that you can time travel through the magic of photos. But as much as the ad man is winning at work, he's failing at home: The pitch happens on Thanksgiving, and though Don hurries back to meet his wife and the kids before they leave for her dad's house, he just misses them. Dylan's classic tune, about a painful split, plays over him sitting, dejected and alone — foreshadowing what's to come for the couple.