The line-up of the band has changed several times: David Hodges leaving in 2002, co-founder Moody left in 2003 (mid-tour), bassist Will Boyd in 2006, followed by guitarist John LeCompt and drummer Rocky Gray in 2007. The last two changes led to a hiatus, with temporary band members contributing to tour performances. In June 2009, it was announced on the Evanescence website that the band was working on new material for a third studio album. Billboard ranked Evanescence #71 on the Best Artists of the Decade chart.
"Lacrymosa" incorporates the Lacrimosa sequence from Mozart's Requiem (1791) throughout the song. The song received mostly positive reviews from music critics who called the song one of the "most memorable track" on The Open Door and Lee described it as an "awesome metal epic".
The song is an alternative and symphonic metal song set in slow tempo. The song was originally written in the key of D-minor but Lee and Balsamo transposed it into E-minor.