It amuses me, in this thread, that so many are amazed that Gyllenhaal can sing. Many film and TV actors can sing, it's simply part of an actor's training. Did it surprise everyone to learn that Streep could sing, or Sarandon, Amy Adams, Kristin Bell, Kate Hudson, James Cordon, Minnie Driver, Emily Blunt, Ewan McGregor, Kate Winslet, Jeremy Renner, Robert Downey Jr, Kerry Washington, Anna Kendrick, Gwenyth Paltrow, Zooey Deschanel and many, many others? It's just part of what you often (not always) learn to do when you go into a career in the performing arts.