He has through years released several albums with like-minded musicians such as the trio POING (with Rolf-Erik Nystrøm and Håkon Thelin), Trygve Seim, Håkon Kornstad, traditional players, and most notably his own ensemble Avant Folk.
Haltli has worked with several composers who have written especially for him; Maja S.K. Ratkje, Bent Sørensen, Atli Ingólfsson, Hans Abrahamsen, Jo Kondo, and others. He has appeared as a soloist with orchestras and worked with iconic ensembles such as the Arditti and the Vertavo quartets, and the Neue Vocalsolisten Stuttgart.
His debut CD ‘Looking on Darkness’ was released on ECM New Series in 2002. He has since released several albums ECM, Hubro, and other quality labels. In 2020 he released ‘Selected Solo Works, Vol. 1-3’ with contemporary works for accordion on the family-run label Svartskog Music Production.
On his 2007 recording ’Passing Images’ (ECM), Haltli is joined Arve Henriksen, Garth Knox, and Maja S.K. Ratkje, for a selection of lyrical explorations of Norwegian folk themes couched in the form of contemporary improvised music. He has developed this theme further on several albums.