Dag Holtan-Hartwig (born April 16, 1991), known professionally as Slopes, is a Norwegian singer, composer and music producer.
Holtan-Hartwig grew up in a musical family in a suburb of Oslo and began playing in bands at the age of twelve. In England, he enrolled at the Liverpool Institute for Performing Arts (LIPA) and performed there in front of Sir Paul McCartney, who gave him important advice. At LIPA, he met fellow Norwegian singer Halvor Folstad and started to work with him. Both got a record contract in Norway. After the training they went their separate ways. Folstad returned to Oslo, and Holtan-Hartwig worked as a producer in London and later in Los Angeles. Returning to Oslo, Holtan-Hartwig and Folstad formed the duo Skinny Days in 2015 and released their debut single Alright Right Now. As songwriters and producers for other artists, Folstad and Holtan-Hartwig have been responsible for billions of streams for artists such as Ava Max, Alan Walker, SeeB, and Julie Bergan.
As Slopes, Dag Holtan-Hartwig has been performing solo since 2021. To that end, he signed a contract with Warner Music.