He is the founder and current managing partner of Norwegian full-service music company MER (which he co-founded in 2012), representing artists such as Alan Walker.

Greve began his career in the music industry in the mid 1990s, when he established the Norwegian hip hop group Spetakkel.

Greve went on to pursue his solo career under the moniker Gest, with the release of his solo-debut I Grevens Tid in 2007.

[4] In June 2016, Walker released his follow-up single "Sing Me to Sleep" (also co-written by Gunnar Greve).

[5] In October 2016, Gunnar Greve signed a publishing deal with Sony/ATV Music Publishing / Stellar Songs Ltd.[6] Today, Greve works actively as an A&R, manager and songwriter for artists, producers and songwriters such as Alan Walker, Paperboys and Mood Melodies.