[1] Pettersen was born in Skien, and took part, aged 14, in the 2003 edition of Melodi Grand Prix Junior with the song "Hekta på brett" that he had written himself.

On 4 December 2010 he appeared at the TV 2 Artist Gala performing "Lean on Me" with Annsofi Pettersen and Mohamed Abdi Farah and in Spring 2011, he appeared as guest artist for the symphonic power metal band Kamelot Pettersen was the lead singer of the progressive metal Above Symmetry together with Robin Ognedal (guitars), Joachim Strøm Ekelund (drums), Nickolas Main Henriksen (keyboards) and Rein Blomquist (bass).

They were originally called 'Aspera', but were threatened with legal action by another band with the same name, forcing the change to Above Symmetry in 2010.

[6] Together with Ognedal, Henriksen and Blomquist he formed the hard-rock band The Scheen in 2013, recruiting Tobias Ørnes Andersen on drums.

[1] In autumn 2011, he took part in TV 2's reality show Skal vi danse[7] (Dancing with the Stars franchise), partnering with Marianne Sandaker.