Most achingly-beautiful music

The slow movement from Mahler's 5th

4th movement(adagietto) from Mahler's 5th; Barber's Adagio for strings(if you really want to ache); Ralph Vaughn Williams' Mass in G minor. The Faure Requiem .

This could be a long list, but I'll mention only the ones that come immediately to mind: Miles Davis's album "Kind of Blue"; Bill Evans & Jim Hall's album "Undercurrent"; several cuts from Art Pepper's album "Shoes of the Fisherman"; Sibelius's "Swan of Tuonela"; duets from Puccini's "La Boheme"; Mozart's "Requiem"; Barber's "Adagio for Strings" (used as death theme in movie "The Elephant Man").

Barber's Adagio for Strings was also used in the Platoon soundtrack from 1986. I would add to the list Albinoni's Adagio, the version from Gary Karr on King Super Analogue is superb and very melancholy. If that's your thing of course. I also like various versions of the Ave Maria, and of course, one must add Beethoven's Moonlight Sonata.

Please forgive the length of this post: I second (or third) the Barber Adagio, Albinoni's as well. Would also add Rachmaninoff 2nd & 3rd Piano Concerti, Keith Jarrett's "Hourglass" from "Staircase/Hourglass/Sundial/Sand" & "My Song" from same release, both on ECM, Lyle Mays' "Close to Home" from his first solo release, Pat Metheny's "Always & Forever" from "Secret Story", Rachmaninoff's Vocalise, 4th movement of Beethoven's Ninth, J.S. Bach's Fugue from the Toccata & Fugue in D min, King Crimson's "Starless" from "Red", Miles' "Blue in Green", Coltrane's "A Love Supreme", Louis Armstrong's "Solitude", Metheney & May's "Sept. 15th" from "As Falls Wichita". Bill Bruford's Earthworks' "It Needn't End in Tears" from their 1st album. King Crimson's "Two Hands" from "Beat". Chopin's Etude 10 in E flat, his "Revolutionary" Etude, and Liszt's Liebestraum. Okay, there's my three.