Dessner has co-written, produced or co-produced songs by Taylor Swift, Ed Sheeran, Michael Stipe, Gracie Abrams, Frightened Rabbit, Ben Howard, Sharon Van Etten, Local Natives, This Is the Kit, Adia Victoria, Lisa Hannigan, Fred Again, Girl in Red, Mustafa the Poet, Brian Eno and Lone Bellow, among others.

Dessner has said that his Jewish background influences his music: "My brother and I have always been fascinated by liturgical religious melodies in Judaism ...

The band's self-titled first album was released in 2001 on Brassland Records, a label Dessner co-founded along with his brother Bryce and Alec Hanley Bemis.

[17] The band released their eighth studio album I Am Easy to Find in 2019 alongside a short film by Mike Mills.

[21] In 2008, Dessner sent Justin Vernon an instrumental sketch of a song called "Big Red Machine" for the compilation album Dark Was the Night.

After 10 years, the pair formed a band called Big Red Machine, and on August 31, 2018, released a self-titled album.

The album was produced by Dessner and featured many guests and many of his previous collaborators, including Ben Howard, Sharon Van Etten, and Taylor Swift.

Van Etten and Dessner spent over fourteen months working in his studio, finally releasing the album to widespread critical success.

Hummingbird received positive reviews, and Pitchfork praised Dessner's production work especially, saying that he "knows how to make things sound good, and there's plenty of richness and depth to these songs.

Frightened Rabbit's fifth album Painting of a Panic Attack, released in 2016 via Atlantic Records, was also produced by Dessner.

[26] He also co-wrote and produced the acclaimed debut of UK songwriter Eve Owen, Don't Let the Ink Dry, released in 2020.

[27] In April 2020, during the COVID-19 pandemic, Dessner was approached by American singer-songwriter Taylor Swift to collaborate on music, and he subsequently produced and co-wrote her eighth studio album, Folklore.

It was a surprise release that debuted to critical acclaim on July 24, 2020, and won Album of the Year at the 63rd Annual Grammy Awards in 2021.

[32] After the release of Folklore, the documentary film Folklore: The Long Pond Studio Sessions and Evermore, artists such as Maya Hawke,[33] Gracie Abrams,[34] Ed Sheeran,[35] King Princess,[36] and Girl in Red[37] expressed interest in collaborating with Dessner and recording songs at his Long Pond Studio.

Dessner and his brother Bryce co-composed the score for Transpecos, which won the Audience Award at the 2016 South by Southwest.

The compilation is a wide-ranging tribute to the songwriting and experimentalism of the Dead which took four years to record, features over 60 artists from varied musical backgrounds, 59 tracks and is almost 6 hours long.

Day of the Dead is the follow-up to 2009's Dark Was the Night (4AD), a 32-track, multi-artist compilation also produced by the Dessner brothers for Red Hot.

Of the 59 tracks on the compilation, many feature a house band made up of Aaron, Bryce, fellow the National bandmates and brothers Scott and Bryan Devendorf, Josh Kaufman (who co-produced the project), and Conrad Doucette along with Sam Cohen and Walter Martin.

A Day of the Dead live performance took place in August 2016 at the second annual Eaux Claires Festival (August 12–13) featuring Jenny Lewis, Matthew Houck, Lucius, Will Oldham, Sam Amidon, Richard Reed Parry, Justin Vernon, Bruce Hornsby, Ruban Nielson and The National.

Forever Love marked a live performance reunion for the Dessner twins and Kjartansson, as both artists had previously collaborated on a six-hour video work, A Lot of Sorrow, which documents the National performing their three-song "Sorrow" for six hours in front of a live audience at MoMA PS1.

The work had its world premiere at the Krannert Center for the Performing Arts in September 2009 as part of the Ellnora Festival.

[41] In 2009, Aaron and Bryce Dessner produced an extensive AIDS charity compilation, Dark Was the Night, for the Red Hot Organization.

In August 2008, Aaron and Bryce performed a collaborative concert with David Cossin, and Luca Tarantino as a part of Soundres, an international residency program for contemporary music and art in Salento, Italy and at the Guitare Au Palais Festival Perpignan France.

In October 2011, Dessner joined his brother to perform "St. Carolyn by the Sea" with the American Composers Orchestra at The World Financial Center in New York City.

Marshall Curry's award-winning documentary Racing Dreams includes music contributed by both Dessner and the National.

In December 2012, Dessner curated a day of Other Voices, an Irish music festival that aired live on RTÉ Two in Ireland.

The first festival took place October 1–2, 2016, under the name "Michelberger Music" in the Funkhaus,[43] the historical radio recording studios of the former GDR.