He has written, played or produced for and with artists such as Tinashe, Solange Knowles, Connan Mockasin, Tei Shi, Sky Ferreira, FKA twigs, Britney Spears, Haim, Caroline Polachek, Florence and the Machine, Carly Rae Jepsen, the Chemical Brothers, Kylie Minogue, A$AP Rocky, Mac Miller, Blondie, Jazmine Sullivan, Sugababes, Turnstile, and Mariah Carey.

From their formation in 2004 until their break-up in 2006, Hynes was a member of the dance-punk band Test Icicles, playing guitar, synth, and occasionally performing vocals.

[8] In early 2007, Hynes, under the name Lightspeed Champion, recorded his debut album in Omaha, Nebraska with Saddle Creek producer Mike Mogis.

A number of Omaha-based musicians appeared on the record, including Mogis himself, trumpet player and pianist Nate Walcott, the Faint's drummer Clark Baechle and guest vocalist Emmy the Great, along with moonlighting members of Cursive and Tilly and the Wall.

Other guest members to have contributed in live shows include Alex Turner of the Arctic Monkeys, Faris Badwan of the Horrors, Frederick Blood-Royale of Ox.Eagle.Lion.Man,[12] Jack Peñate and Eugene McGuinness as well as We Are Scientists' Keith Murray on Late Night with Conan O'Brien on 6 June 2008.

Backed by a full band, Hynes appeared at the NME 2008 Awards, broadcast on Channel 4 on 29 February 2008, dressed as characters from Star Wars, including Princess Leia on the drums.

Hynes also performed with We Are Scientists at the Glastonbury in 2008 (John Peel Stage)[14] and appeared at Belgian music festival Pukkelpop in August 2008.

[citation needed] By the end of what became a two-year touring period, Hynes had suffered severe damage to his throat, and had to undergo extensive surgery.

[15] He took a two and a half-year hiatus from touring, appearing occasionally to play shows in New York and a top billed slot at the Carling Festival in 2009.

In April 2010, Hynes returned to the Barbican to perform with the Triffids for a special concert in honour of their singer David McComb along with Warren Ellis, Tindersticks and members of the Brian Jonestown Massacre.

With Lightspeed Champion on effective hiatus, Hynes decided to concentrate on a new musical project more focused on R&B and electronica, called Blood Orange.

The album features guest appearances, including performances from David Longstreth (Dirty Projectors), Caroline Polachek (Chairlift), Samantha Urbani (Friends), Clams Casino, Despot, Adam Bainbridge (Kindness), Skepta and more.

[25] On 19 July 2018, he announced his fourth studio album under the Blood Orange moniker, Negro Swan, and released in the following week its first two singles: "Charcoal Baby" and "Jewelry".

[citation needed] Hynes contributed music to the 2010 film MacGruber, including the duet "Rock My Body" with Saturday Night Live cast member Kristen Wiig.

In late 2011, he produced Australian noise pop duo Bleeding Knees Club's debut album Nothing to Do, which was released on 2 March 2012.

Hynes and collaborator Ian Isiah co-created and performed an adaptation of "Grateful" by gospel singer Hezekiah Walker for a fashion show by New York-based designer Telfar Clemens.

[35] Hynes co-wrote Blondie's single "Long Time" with Deborah Harry, which was included on the band's eleventh album Pollinator.

[38] Hynes has collaborated several times with composer Philip Glass, performing his piano Etudes for radio, at Carnegie Hall and the Kennedy Center.