Rosser's first gig was with high school punk band called "The Warthogs" who covered The Clash, The Ramones and the Sex Pistols.

[1] Rosser studied chemical engineering at Sydney University[1] and stayed there for four years until he left to pursue a career as a musician.

After a year of touring with the band, Wolfmother split up temporarily while frontman Andrew Stockdale worked on his solo album Keep Moving.

In 2016, Rosser joined children's rock 'n' roll band Bunny Racket, and performed with them at Splendour in the Grass in July of that year.

[8][9] In 2008, Rosser launched a beer called Skinny Blonde along with winemaker Richie Harkham and artist Jarod Taylor.