is a Berlin-based Danish composer working with a multidisciplinary approach to musical performance and the concert situation. He studied composition with Karl Aage Rasmusen, Bent Sørensen, Mathis Spahlinger and Gabriel Valverde in Denmark, Germany and Argentina. Since 2008 he has been a lecturer of composition at the Royal Academy of Music in Aarhus. He was visiting professor at the Norwegian Academy of Music in Oslo in 2013–14 and lecturer at the Summer Courses for New Music in Darmstadt in 2014–16. In 2017 he was a guest professor at the University of Arts in Berlin. Since 2018 he has held the position of professor in the Composition and Music Theatre department at Bern University of the Arts and associate professor at the Royal Academy of Music in Aarhus. 

Steen-Andersen’s works live in the passages between the simple and the complex, in a cross-aesthetical field where orchestral music, video art, choreography, performance, music theatre and installation are mixed with pop-cultural elements and game-aesthetics in surprising and thought-provoking ways. His works therefore present a pronounced expansion of music, where no material is too fine or too simple to be given careful attention, taken apart, and assembled anew. No matter the musical material or concept, it is done with a precise sense of both the music of movement and the ever-present logic of contemporary mediatisation. His numerous awards and accolades include notable the Kranichsteiner Music Award, International Rostrum of Composers, DAAD residency in Berlin, three Carl Nielsen Prizes, Kunstpreis Music from the Academy of Arts in Berlin, Nordic Council Music Prize, SWR Orchestra Prize, Ernst von Siemens Composers Prize, Mauricio Kagel Music Prize. In 2016 he was elected a member of the German Academy of the Arts, followed in 2018 by the Royal Swedish Academy of Music.

His works have been commissioned by ensembles, orchestras, and festivals such as ensemble recherche, Neue Vokalsolisten Stuttgart, SWR Orchestra, Radio France Philharmonic Orchestra, Ensemble Ascolta, JACK Quartet, Ensemble Modern, Danish National Chamber Orchestra, Danish Royal Opera, Copenhagen Philharmonic, Oslo Sinfonietta, 2e2m, Donaueschinger Musiktage, Ultraschall, Wittener Tage für Neue Kammermusik, and Éclat. He has worked with the leading new music ensembles including Klangforum Wien, Collegium Novum Zurich, ICTUS, Arditti Quartet, London Sinfonietta, Oslo Sinfonietta, Ensemble intercontemporain, asamisimasa, and NADAR. 

Selected works (since 2007): Chambered Music for 12 instruments and sampler (2007), Ouvertures for amplified guzheng, sampler and orchestra (2008–10), Black Box Music for percussion solo, amplified box, 15 players and video (2012), Inszenierte Nacht, stagings of pieces by Bach, Schumann, Mozart and Ravel in cooperation (with Ensemble Ascolta, 2013), Piano Concerto for piano, sampler, orchestra and video (2014), Korpusfor three Harry Partch instruments and 7–8 players (2015), if this then that and now what for four actors, two trombones, four percussionists and 12 strings (2016), Asthma for accordion and video (2016), TRIO for symphony orchestra, big band, choir and video (2019), The Loop of the Nibelung (Run Time Error @ Bayreuth) for performer, two singers, 15 musicians and video (2020), Walk the Walk, music theatre for four performers, treadmills, objects, light and smoke (2020), TRANSIT, staged concert for tuba, objects and endoscopes (2021), THE RETURN (Run Time Error @ Venice feat. Monteverdi), music theatre for three singers, Baroque ensemble, objects and video (2022), Music in the Belly, stagings of Stockhausen’s work for six performers (2022), Don Giovanni’s Inferno, opera for six singers, five on-stage musicians, male choir, orchestra, electronics and video (2023), No Concerto for actor, pianist, orchestra, video, electronics and light (2024).