Bley's "Mechanical" Music.

After her husband's death in 1979, Sue Graham Mingus worked to keep his legacy alive, forming a repertory ensemble devoted to playing his compositions. She died Sept. 24. Originally broadcast in 2002.

Williams was a dazzling player and a favorite at Fresh Air. She died March 10 at 73. We'll listen back to her 1997 performance and interview.

We conclude our tribute to Sondheim by listening to archival interviews with collaborators and performers, including Stephen Colbert, James Lapine, Paul Gemignani and Lin-Manuel Miranda.