What Makes a Broadway Tune a Showstopper

In his new book, "Showstoppers! The Surprising Backstage Stories of Broadway's Most Remarkable Songs," critic Gerald Nachman draws on in-depth interviews with icons of musical theater to explore what makes certain songs "knock us out" and send audiences home humming. These tunes "often become a vital part of Americana, firmly lodged in the country's collective memory" he writes. We talk with Nachman about his favorite hits, his 50 years as a theater critic and what worries him about today's musicals.