Born in Estonia, he finished his studies in St. Petersburg under Maestro Mariss Jansons. In the early stages of his career, he worked closely with both Rudolf Nureyev and John Neumeier, leading to invitations from leading theatres and ballet companies. In addition to France and all major opera houses in Scandinavia, Pähn has conducted at La Scala, Semperoper Dresden, Berlin State Opera, Bavarian State Opera, Hamburg State Opera, Leipzig Opera, Vienna State Opera, San Carlo, Finnish National Opera and Duth National Opera, among others. From 2012 to 2019, he was the chief conductor and Artistic Director of Estonian National Opera. His premieres there included Gounod's Faust and Romeo et Juliette, Wagner's Tannhäuser and The Flying Dutchman, Hindemith's Cardillac, Mozart's Die Zauberflöte, Strauss' Arabella, Verdi's Aida and Bernstein’s Candide among others.