Its reception has generally been 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".

[6] On November 5, 1938, a selected audience was invited to Studio 8H in Rockefeller Center to watch Toscanini conduct the first performance; it was broadcast on radio and also recorded.

The lower strings come in two beats after the violins, which, as Johanna Keller from The New York Times put it, creates "an uneasy, shifting suspension as the melody begins a stepwise motion, like the hesitant climbing of stairs".

[3] NPR Music said that "with a tense melodic line and taut harmonies, the composition is considered by many to be the most popular of all 20th-century orchestral works.

[9] According to music theorist Matthew BaileyShea, the Adagio "features a deliberately archaic sound, with Renaissance-like polyphony and simple tertian harmonies" underlying a "chant-like melody".

"[7][11][12] Alexander J. Morin, author of Classical Music: The Listener's Companion (2001), said that the piece was "full of pathos and cathartic passion" and that it "rarely leaves a dry eye".

[2] Reviewing the premiere performance in 1938, Olin Downes noted that with the piece, Barber "achieved something as perfect in mass and detail as his craftsmanship permits".

[11] In an edition of A Conductor's Analysis of Selected Works, John William Mueller devoted over 20 pages to Adagio for Strings.

[13] Wayne Clifford Wentzel, author of Samuel Barber: A Research and Information Guide (Composer Resource Manuals), said that it was a piece usually selected for a closing act because it was moderately famous.

[16][17] In 2019, NPR revisited the piece, with writer Anastasia Tsioulcas suggesting it arrived at "the right moment, when America was still hurting from the Great Depression and Europe was sliding into war."

She continued by noting how young people reinterpret "America's semi-official music for mourning" as an expression of joy, using the example of Dutch DJ Tiësto's remix of Adagio for Strings as a dance music anthem,[18] which caught the attention of the 2004 Olympics Organizers in Athens (ATHOC) and is included on Parade of the Athletes, Tiësto's retrospective mix of his live set performed during the opening ceremony.

They include:[6] Strickland, while assistant organist at St Bartholomew's Church in New York, had been impressed by Toscanini's recording of the work and had submitted his own arrangement for organ to Schirmers.

Strickland, subsequently appointed wartime director of music at the Army's Fort Myer in Virginia, became a champion of Barber's new compositions.

[3][38][39] More comedic or lighthearted uses of it have appeared in the film Amélie (2001) and on episodes of the sitcoms Seinfeld, The Simpsons, American Dad!, and South Park.