At heart, the Norwegian keyboard phenomenon Leif Ove Andsnes is a musician’s musician. As artistic director of the Rosendal Chamber Music Festival for 10 summers, he has attracted like-minded colleagues and a discerning public with programs of uncommon substance and appeal. His formula, if we can call it that, typically showcases an immortal on the order of Mozart or Beethoven alongside a more regional voice or two. For his final season, Andsnes is concentrating on Norwegians associated with Hardanger, the region surrounding Rosendal. Edvard Grieg (1843–1907), whose songs feature prominently, needs no introduction. Geirr Tveitt (1908–81), who collected and rewrote local folksongs, will be a discovery, especially for international visitors, likewise Knut Vaage (born in 1961), who is represented by several world premieres. Fans attached to Rosendal’s postcard-perfect fjord-side setting and aristocratic country charm will rejoice to hear that while Andsnes is stepping down from the top job, he’ll be pitching in as artistic adviser for a new series beginning in 2026, leadership and other particulars to be announced. —Matthew Gurewitsch