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…