"Lacrymosa" was written by Amy Lee and Terry Balsamo, produced by Dave Fortman, and recorded in a chapel near Seattle, Washington. In a number of interviews, Lee revealed that everyone asked about a collaboration between her and Mozart. She further stated that she always wanted to make Lacrimosa from Mozart's Requiem a metal song, later adding that The Open Door was "the time for that, for trying things I hadn't been brave enough to try before." In an interview with VH1 News, Lee further explained the inspiration behind the song: "I saw Amadeus when I was nine years old and fell in love with Mozart. The part of Mozart's Requiem called "Lacyrmosa" [sic] is my favorite piece of music ever. I always wished we could cover it, but with programming and guitars and make it cool. It's our moment to try all the things I wanted to and couldn't, so I started messing with it in Protools. Terry wrote some riffs and turned it into this awesome metal epic."