He originally wrote it as the second movement of a string quartet in 1936, but within two years arranged it for string orchestra. In this form, it became not only his most popular work, but also an unofficial American anthem of mourning, played after the deaths of Presidents Roosevelt and Kennedy. The two versions, string quartet and string orchestra, make their own separate effect. The string quartet version, as you would expect, is intimate and occurs in the context of other movements. Not surprising for an artist with wide literary interests, Barber found initial inspiration in a passage from Vergil's Georgics describing how a rivulet gradually becomes a large river.
Sequence is the most elementary form of variation, and most composers learn to use it sparingly.
Barber builds an entire piece from it. There's no real complication to the Adagio , no technique or unusual turn of harmony that holds the secret of its success. One cannot even pick one passage over another, any more than you can say one point makes the beauty of an arch. This is a masterpiece. Use of text, images, layout, format, look, or feel of these pages, without the written permission of the copyright holder, except as specified in the Copyright Notice , is strictly prohibited.