For 10 points, identify this work for string orchestra by the composer of Vanessa, Samuel Barber.
This piece was described by its conductor at its premiere as "simplice e bella." Orchestrated by William Strickland for the solo organ, this work begins with the first violins playing a B flat in unison and grew out of its composer's String Quartet in B Minor, Opus 11. Inspired by Virgil's Georgics, this work was later used in its composer's setting of his choral work Agnus Dei. This piece was premiered under conductor Arturo Toscanini in and was played during the announcements of the deaths of Franklin D. Roosevelt and John F. Kennedy. For 10 points, identify this work for string orchestra by the composer of Vanessa, Samuel Barber.
This piece was described by its conductor at its premiere as "simplice e bella."
Adagio for Strings