The group, which mixes classical music with electronic pop, has had huge hits such as "Rather Be", "Rockabye", "Solo" and "Symphony" - the latter with Zara Larsson - and has several billion streams on Spotify.
Norwegian artist Fjellrev, Sarettii and Anis Don Demina are also confirmed, the festival announced. The festival is being held in Umeå on June 5–7.
Joakim Lundell, Hooja, Soppgirobygget and Ida-Lova, among others, have already been confirmed.
