Most achingly-beautiful music

Many of Pat Metheny's tunes qualify for me.

I'm new here and am absolutely floored by this thread, its, its, its, you know! I started to read some of the comments and them went back and started to copy and paste as much as I could, as this is a wellspring of information Thanks to all!!
Also to Terryhut, if you really want ache added to the aural add a dash of visual... Galipoli/Albinoni... we all know the scene.

As to Golfrok's nomination of Pat Metheny, allow me to specify his rendition of 'Ferry, Cross the Mersey' on the recently released 'One Quiet Night' Album.

For all you youngsters out there, that tune was originally a hit for Gerry and the Pacemakers on the first wave of the British Invasion - what would that be '64, '65? Had some of my first slow dances to that one.

There has been some achingly beautiful music written in the last 400 years. Interestingly, all of my choices are from the last century. Here goes:

Samuel Barber- Adagio for Strings
Gustav Holst- The Planets
John Coltrane- Ballads

Mahler: Ich bin der Welt: from Ruckert Songs
Mahler: Der Abschied: from Das Lied von der Erde
Mahler: Adagietto: from Symphony No. 5
Rachmaninov: 18th variation from Paganini Variations
Korngold: Marietta's song: from Die tote Stadt

The renditions of these pieces that I prefer are respectively:

(1) Janet Baker
(2) Janet Baker or Brigitte Fassbaender or Dietrich Fischer- Dieskau (with Kletzki, but NOT Bernstein)
(3) Barbirolli/New Philharmonia
(4) Stephen Hough, Andrew Litton/Dallas SO
(5) Renee Fleming