His style of music has been described as "blue wave"[5] and "slacker rock",[6][7] or, by DeMarco himself, "jizz jazz".

[8] DeMarco was born in Duncan, British Columbia, on Vancouver Island, and raised in Edmonton, Alberta.

[18][19] Living in the Killarney neighbourhood, he released a self-produced album, Heat Wave, as a part of the indie rock project Makeout Videotape in 2009.

[19] He was joined by Alex Calder and Jen Clement, signed to Unfamiliar Records, and toured with Vancouver band Japandroids in 2009.

[21] Rock and Roll Night Club impressed his new label enough that they agreed to release a full-length follow-up album.

[24] On January 21, 2014, DeMarco announced the release of his upcoming second album, Salad Days, along with debuting the lead single "Passing Out Pieces".

Later that evening, he hosted a listening party in New York City (where DeMarco was based) for fans to hear Another One, where they could get free hot dogs if they donated to a food bank.

[42] Mitski responded to the controversy on Twitter, stating, "I'm 100% sure mac & I just went fishing in the same part of the collective unconscious!".

[44] On September 7, 2020, DeMarco was featured on a collaboration with English artist Yellow Days, entitled "The Curse".

His return to the stage was marked by changes to his live band, with the departure of longtime members Joe McMurray, Andrew White and Jon Lent, and the addition of Darryl Johns (bass) and JD Beck (drums).

Andy White confirmed his departure shortly afterwards stating: "Mac's an old friend, life is long, and no one knows the future.

The fourteen-track album was recorded in different locations during a road trip from Los Angeles to New York City.

[51] On April 21, 2023, DeMarco released his first compilation album titled One Wayne G, online only, without any prior announcement.

Of the 199 tracks, 18 have full titles and lyrics, the remainder being instrumentals or having simple scratch vocals, suggesting the compilation is composed of demos as well as finished pieces.

DeMarco's style employs the use of flat drums (little or no reverberation or dynamic range compression), chorus and vibrato effects on the guitar and a generally lazy atmosphere à la soft rock records, muted and low frequency bass guitars.

He has mentioned Shuggie Otis, Black Sabbath, Christopher Cross, Siouxsie and the Banshees, Jonathan Richman, Genesis, Sting and Weezer as favourite artists.

[58][59] His guitar-based compositions have moved from glam-inspired works to what reviewers describe as "off-kilter pop"[21] or "folk rock".

[61] DeMarco has pointed to artists such as John Maus, Ariel Pink, Brian Eno, Daniel Lopatin, Isao Tomita and R. Stevie Moore as influences on his reel-to-reel production style.

Additional models include a Rhodes piano, a Moog Realistic MG-1, a Prophet-5, a Roland Juno 60, JX-3P, and a Yamaha DX100.

[67] Previously based in the Far Rockaway neighborhood in Queens, New York,[68] he currently resides in Los Angeles where he has regularly hosted jam sessions with musicians and friends such as Thundercat and the late Mac Miller.