Nina Costanza wrote:

>The saddest and one of the most beautiful works for me is Mahler's
>Adagietto in the Fifth Symphony...

FWIW, my impression is that while Barber's Adagio is the quintessential
(or perhaps "official") "sad piece" -- i. e., played on the media when a
true disaster strikes -- in America, Mahler's Adagietto plays the same
role in Europe (at least on the continent).

-Margaret Mikulska