[5] As an artist for "Virginia Records" she has had hits like "Samurai", which became the most broadcast song on Bulgarian air for 5 weeks, "Igraem s teb do kraya", featuring Kristo, "Nevuzmojni sme sami" and "Dokrai (Докрай)".

In 2013 he began his solo career and released the songs "Po-dobre, che razbrah" and "Dilar na lubov".

He has worked as a voice actor in the Bulgarian dubbing of animated films like Frozen, Tangled, or The Muppets, among others.

Trey has written music for artists like Dua Lipa, Bebe Rexha, Julie Bergan and Alexandra Stan.

His performance of Whitney Houston's "I Have Nothing" on America's Got Talent in 2017, where he eventually reached the Semi-Finals after getting the Golden Buzzer from guest judge Seal, accumulated over 270 million views on social media.

After America's Got Talent, he released two singles, "Come Alive" and "Blind Faith", and began working on his debut album with Symphonix International.

On 12 March 2018, it was announced by Bulgarian National Television that Equinox would represent Bulgaria in the Eurovision Song Contest 2018.

The song was composed by Borislav Milanov, Trey Campbell, Joacim Persson and Dag Lundberg.