I have rendered several pieces from Mozart's Requiem in D Minor, the Intro and first part and then the waltz, called Lacrimosa. I made use of the GPO4 Choir, some of which I exported from Cubase, just the choir tracks, gave them some audio treatment like chorus etc. then brought them back into the mix as an audio track, sometimes in multiple instances, and blended that with the existing choir tracks. Otherwise though, I pretty much left the music intact. Mozart wrote this requiem for a Count who commissioned it in honor of his recently deceased wife. This was the summer of 1791 and Mozart died on December 5, 1791.
Mozart Requiem - excerpts - GPO4 + sd cisco