This edition of Musician's Spotlight features one of the linchpins of late 20th-century American popular and folk music, the singer who popularized classic songs by writers both beloved and unknown: Joni Mitchell, Woody Guthrie, Leonard Cohen, Pete Seeger, Ian Tyson, Bob Dylan, Stephen Sondheim, Kurt Weill -- and "trad. arr. Collins." Starting with 1961's "Maid of Constant Sorrow" all the way up to 2017's "Everybody Knows" (with Stephen Stills) and into the present, her recording and performing career has thrived alongside a passion for social justice. Judy Collins is John Floridis's guest.