Many composers have dedicated works to him, including Luca Francesconi, Magnus Lindberg, Kaija Saariaho, Esa-Pekka Salonen, Tan Dun, Rolf Wallin, Pascal Dusapin, Fred Lerdahl (Arches), and Betsy Jolas.
Karttunen regularly performs with various chamber ensembles, including the Sons of Chipotle with John Paul Jones, the Zebra Trio with violinist Ernst Kovacic and violist Steven Dann, a cello-piano duo with Nicolas Hodges, and the Tres Coyotes with Magnus Lindberg and John Paul Jones.
Together with Kaija Saariaho, Jean-Baptiste Barrière and Muriel von Braun, Karttunen created www.petals.org, a nonprofit organisation for distributing music in different forms over the internet.
[1] The group premiered with concerts in Seoul, South Korea, and at the Pit Inn in Tokyo, Japan, that year, joined by musicians Jim O'Rourke and Otomo Yoshihide.
Karttunen's teachers included Erkki Rautio, William Pleeth, Jacqueline du Pré and Tibor de Machula.