His work as a film composer includes scoring the 2021 documentaries All Light, Everywhere and Ascension, both released as soundtrack albums by Milan Records, as well as Francis Ford Coppola's Twixt (with Osvaldo Golijov).

He graduated from Babylon High School in 1999 where he was a member of the local ska band Channel 59 alongside Tim Daniels of The Complete Guide to Everything.

[citation needed] He followed those two albums with a set of records made up of sine wave compositions, Green Cobra Is Awesome Vs The Sun and Goose on the Loose.

"[13] The collaborative video-art piece Ultimate Reality was released as a DVD in November 2007 by Carpark Records and marked a return to composing music for others to perform.

The sonic pieces were set to collaged and heavily altered video created by Deacon's long time friend and collaborator Jimmy Joe Roche.

Deacon has described the album as representing his conflicted feelings toward the country and world he calls home: "The inspiration for the music was my love of cross-country travel, seeing the landscapes of the United States, going from east to west and back again over the course of seasons.

[20] In his A− review of the album for Consequence of Sound, Derek Staples noted that "the universal motifs of his discography are now refracted through a more personal lens", and praised the record's "new lyrical depth".

[22] Deacon produced and co-wrote the album Riddles by Ed Schrader's Music Beat, released March 2, 2018 on Carpark Records.

[23] Writing for NPR's All Songs Considered, Bob Boilen described Riddles as "a fascinating piece of work that is both ugly and beautiful, often at the same time", likening its sound to late-1970s records by Suicide and Pere Ubu.

[24] Nina Corcoran noted in Pitchfork that "You can hear Deacon's style, especially that of 2012's America, all over this album: the gleeful piano fluttering in 'Riddles,' the manic percussion buried in fuzz on 'Dizzy Devil,' the thick wall of synth on 'Kid Radium.

On February 3–4 the Kitchener-Waterloo Symphony conducted by Edwin Outwater premiered Deacon's first orchestral works,[31] "Fiddlenist Rim" and "Song of the Winter Solstice for orchestra and electronics".

The piece was premiered at the 2012 Ecstatic Music Festival and was performed by the Calder Quartet, NOW Ensemble and Deacon on electronics controlling a Disklavier player piano.

The program contained compositions by Cage and others influenced by the composer, including two works by Deacon, "Take A Deep Breath" and "Bottles" from "Ghostbuster Cook: Origin of the Riddler".

[43] When playing solo he usually performs on floor level within the audience, his musical devices being set up on a low table, and surrounded by the crowd.

In stark contrast to Deacon's electronic performances, the Bromst tour was with a 14-person ensemble of members of various Baltimore bands including So Percussion, Future Islands, and Chester Gwazda.

[44] In the fall of 2009, Dan Deacon was forced to cancel the small remainder of his North American tour, which included shows at Rensselaer Polytechnic Institute in Troy, New York and Connecticut College in New London, Connecticut due to health complications involving a battle with acute sciatica, all of which were rescheduled in winter of 2010.

[49] In September 2010, Deacon collaborated with video artist Jimmy Joe Roche at the Incubate festival in Tilburg, The Netherlands.

[50] Deacon's score for Theo Anthony's 2017 documentary Rat Film was issued on October 13, 2017 as the inaugural release on the new Domino Soundtracks imprint.

[51] During the recording of the score, Deacon experimented with the rodent subjects, placing rats onto a custom fiberglass table with sensors on each corner.

[56] Deacon also contributed original music to the score of Francis Ford Coppola's 2011 horror film Twixt, starring Val Kilmer.