Holsten comes from a musical family. He played the title role in a Norwegian language musical production Oliver that played in the Lillestrøm Cultural Center in 2003 when he was just 10 years old. He also ended up with roles in other stage presentations like Skatten på Sjørøverøya and Scrooge and at age 17 started putting musical materials online, ending up with a contract with the Circle management group.
Holsten came to prominence when he was featured in the vocals of Norwegian duo Broiler's 2014 hit "Rays of Light" although he was not credited in the official title of the release. The song reached number 1 on the Billboard Hot Dance Club Songs chart and number 2 on US Billboard Dance/Electronic Songs chart, also charting on VG-lista, the official Norwegian Singles Chart. His vocals were featured also on Martin Björk 2015 song "Ricochet", charting number 1 on iTunes in Sweden. Holsten co-wrote «Happiness», the debut single South Korean girl group Red Velvet released in 2014 alongside Will Simms, Chad Hugo (of The Neptunes) and Anne Judith Wik (of Dsign Music). The song made it number 1 in South Korean Gaon Music Chart.
Holsten released his debut single titled "Layers" written by Holsten along with Katrin Fröder, Anders Kjær and Bernt Rune Stray. A music video was also launched for the song directed by Christian Bastiansen featuring dancer Ragnhild Skar Hajum.
In 2016 he got signed to Warner Music Norway and shortly after he released his single "On My Own" with Norwegian production duo Rat City. The single led him to join the official Norwegian Charts Tour, even though the song never made it to the hit-list itself.