Kalbakken are/were the brother-sister duo of Dave and Kirsty Birchall, who drew their repertoire from Norwegian folk songs from their childhood.
They released one CD on Manchester label Little Red Rabbit Records in 2009, with extra musical contributions from Nicolas Dobson (percussion) and Paddy Steer (double bass).
This is one of a few gigs they played at (/outside) the Klondyke Snooker and Bowls Club in Levenshulme between 2006-2009. I think I've narrowed it down to this date based on the adjacent gig photos on my film and the obviously favourable weather. I am fairly sure this photo shows where they played the actual set, whereas the photo on the edge of the green is more likely to have been some kind of warm-up.
As you can see from the discography link on his website (evidence of Kalbakken CD about 4/5 way down) Dave is still very active in the Manchester improv and DIY music scene.