[5] Blay took a series of day jobs in her late teens, including one at Southwark Council, but found full-time employment incompatible with her lifestyle and decided to pursue music professionally.

[7] Blay released her debut single, "On My Own", in April 2008, followed by performances at the Glastonbury Festival and on the TV programme Later... with Jools Holland later in the year.

[6][8] Following Blay's appearance at the American music festival SXSW, her debut EP, Querelle, was released in the US via Iamsound Records in August 2009 to positive reviews from Prefix and Spin magazines.

[10][11][12] To mark the EP's release, Blay issued a free mixtape featuring her own tracks alongside songs by artists including Late of the Pier and Diana Ross.

[13][14] Also in 2009, Blay appeared alongside Alessi's Ark, Micachu, Róisín Murphy, and Sinéad O'Connor on a cover of Chaka Khan's "I'm Every Woman", a charity single released to support ActionAid.

[15][16] Blay was expected to release a full-length album in 2009, with production from Blue May, Dave McCracken, Joseph Mount (of Metronomy), and Mark-Anthony Tieku.

[39][40] The track was premiered on August 12 on BBC Radio 1 by Clara Amfo,[41] and was subsequently selected as Adele Roberts' "Tune of the Week".

[45] In 2014, Blay and Alexander Burnett (of Australian band Sparkadia) formed a deep house duo called Antony & Cleopatra, who featured on three singles in 2014: Lancelot's "Givin' It Up", Beni's "Protect", and Sammy Bananas' "Money Time".

[53] As CocknBull Kid, Blay's visual imagery has been inspired by Mexican folk art and colours prominent in South American culture,[54] and she wears a bespoke headress for her live performances adorned with fairly lights, peace symbols, and skulls.

[55] American singer Shamir has cited CocknBullKid (Blay) as one of his major influences, and had himself tattooed with a lyric from "Hold on to Your Misery".