Requiem for the Living
Two years ago, at the graduation ceremony for the students of the college where I teach, the student chorale sang a piece of music I had never heard before. The performance was excellent, and after the ceremony, I asked around in order to discover the name of the song. It turned out to be from a longer piece by Dan Forrest called "Requiem for the Living." The chorale sang the "Agnus Dei" portion of the longer work.
I'm including a link to the entire work, but the link starts at the beginning of the Agnus Dei section. It's about seven minutes but well worth the time. If you enjoy the shorter piece, go back and listen to the entire work. There are some quite beautiful moments throughout.