Following his cello and guitar studies, Michel Petrossian went on to study composition, analysis, and orchestration with Isabelle Duha and Alain Louvier, among others. At the Conservatoire National Supérieur de Musique et de Danse in Paris, he joined the composition class, in which he worked with Guy Reibel, and followed courses in analysis, orchestration, Indian music, and ethnomusicology. He completed his studies in 2001, obtaining the Diplôme de Formation Supérieure en Composition.

Keen to make the music of his time better known, in 1998, together with the composer Jérôme Combier, he founded the Cairn ensemble, made up of pupils of the Conservatoire de Paris. Right from the first year of his studies, he received requests and commissions, including one for a work for piano from the Musée de l’Armée (which was premiered at the Hôtel des Invalides), an invitation to the Göteborg Art Sounds Festival (with a work commissioned and premiered by the KammerensembleN), a residency at the CNR in Limoges, etc.

He also wrote the music for an experimental film that was presented at the Cité de la Musique and on television, as well as at festivals in Prague and London. Following a composition course, he was selected for a double residency in Canada, with the Nouvel Ensemble Moderne, and - at the Fondation Royaumont - with the L’Instant Donné ensemble. The Académie des Beaux-Arts de l’Institut de France awarded him the Prix Veuve Buchère. Most of his works have been broadcast on France Musique and France Culture.

Later, he became interested in ancient civilisations and in philology and undertook in-depth studies of a number of languages, including Hebrew, Greek, Ugaritic, Aramaic, Babylonian, Old Church Slavonic, and Armenian at the École des Langues et des Civilisations de l’Orient Ancien and at the Sorbonne, where he obtained a master’s. He spent a year at the École Biblique et Archéologique Française in Jerusalem, where his studies on the ground led him to develop an interest in the music of the ancient Near East. He has been asked to give course on the subject in Jerusalem in 2014.

He is currently working on an opera project with the US librettist and author Leslie Dunton-Downer, winner of the Berlin Prize for 2013-2014. For this collaborative project, Michel Petrossian has set out to create a synthesis on the basis of his knowledge of the two spheres of music and philology with a view to developing a new kind of vocal writing.