Currently listening to Samuel Barber's "Agnus Dei." What a treat...
For those who don't know, Agnus Dei is a choral version of Barber's "Adagio for Strings," a tune you may be familiar with if you've seen the movie "Platoon," (though I have not seen it). Arguably one of the most emotionally moving pieces that I've ever heard, adding voices puts a whole new spin on the song, though the outcome is just as haunting as the original, if not more so. I would highly recommend it.