Jack Michael Antonoff (born March 31, 1984) is an American singer, multi-instrumentalist, songwriter, and record producer. Antonoff is the lead singer of rock band Bleachers, and was a guitarist and drummer in the pop rock band Fun. He was previously the lead singer of the indie rock band Steel Train. Aside from his work with Bleachers and Fun, Antonoff has worked as a songwriter and record producer with various artists, including Taylor Swift, Lorde, St. Vincent, Florence and the Machine, Lana Del Rey, Fifth Harmony, Kevin Abstract, Carly Rae Jepsen, the Chicks, Tegan and Sara, and Clairo. Antonoff has often been credited with having a significant impact on the sound of contemporary popular music. Antonoff was previously married to actress Margaret Qualley (August 2023 to September 2026) and prior to that was in a long-term relationship with actress Lena Dunham.