Most achingly-beautiful music

I only have one that stands out, in the sad category. Alison Kraus, Jacob's Dream.

Mazzy star/ hope Sandoval.

Saint-Saëns - The Swan
Melanie Safka - The Saddest Song
Roy Harper - Davey
Janis Ian - Stars
Sweet Sixteen - The Fureys, The Old Man
Joan Baez (cover) - Forever Young
Albatross - Peter Green
La Petite Fille de la Mer - Vangelis

Well, maybe not "most" but make that only "achingly beautiful" and check out Tim Finn's "Imaginary Kingdom"...several tracks qualify for me (Astounding Moon; Salt to the Sea; Winter Light).

I had a group of guys over a few weeks back and one brought a CD recording of "Pavorotti & Friends for Guatemala and Kosovo". One of the cuts really touched me and cuts the cloth of achingly beautiful to my ears "Tu che m' hai preso il cor" sung by Laura Pausini and Luciano Pavorotti. It is the unique voice of Pausini on this piece that caught my ear. There are versions of it on youtube, check it out, it is too beautiful to me. Cynics beware, it's probably not for you!