Adagio for Strings is a work by Samuel Barber, arguably his best known, arranged for string orchestra from the second movement of his String Quartet, Op. 11.
Barber finished the arrangement in 1936, the same year that he wrote the quartet. It was performed for the first time on November 5, 1938, by Arturo Toscanini conducting the NBC Symphony Orchestra in a radio broadcast from NBC Studio 8H. Toscanini also played the piece on his South American tour with the NBC Symphony in 1940.
Its reception was generally positive, with Alexander J. Morin writing that Adagio for Strings is "full of pathos and cathartic passion" and that it "rarely leaves a dry eye." The music is the setting for Barber's 1967 choral arrangement of Agnus Dei. Adagio for Strings can be heard in many TV shows and movies.
Barber's Adagio for Strings began as the second movement of his String Quartet, Op. 11, composed in 1936 while he was spending a summer in Europe with his partner Gian Carlo Menotti, an Italian composer who was a fellow student at the Curtis Institute of Music. The inspiration came from Virgil's Georgics. In the quartet the Adagio follows a violently contrasting first movement (Molto allegro e appassionato) and is succeeded by music which opens with a brief reprise of the music from the first movement (marked Molto allegro (come prima) – Presto).
In January 1938 Barber sent an orchestrated version of the Adagio for Strings to Arturo Toscanini. The conductor returned the score without comment, which annoyed Barber. Toscanini then sent word through Menotti that he was planning to perform the piece and had returned it simply because he had already memorized it. It was reported that Toscanini did not look at the music again until the day before the premiere. On November 5, 1938, a selected audience was invited to Studio 8H in Rockefeller Center to watch Toscanini conduct the first performance, a radio broadcast which was also recorded. Initially, the critical reception was positive, as seen in the review by The New York Times's Olin Downes. Downes praised the piece, but he was reproached by other critics who claimed that he overrated the piece.
Toscanini conducted Adagio for Strings in South America and Europe, the first performances of the work on both continents. Over April 16–19, 1942, the piece had public performances by the Philadelphia Orchestra conducted by Eugene Ormandy at Carnegie Hall. Like the original 1938 performance, these were broadcast on radio and recorded.