We're back in New York City with architect Nick Potts for a walking tour of the Upper West Side to learn how apartment living was revolutionized by the apartment hotels of that part of the city since the late 1800s. He starts with The Dakota, a ground-breaking apartment building that later was, of course, the home of John Lennon and Yoko Ono. Also, find out why so many musicians like Rachmaninoff, Mahler, and Stravinsky all lived in The Ansonia. Fascinating.