He moved to Canada in 1990 and created the musical ensemble Constantinople, assuming the roles of both artistic director and composer.

[3] From 2002 to 2005, Tabassian was part of the research group on the history of Mediterranean music in the international MediMuses project and collaborated on various recording endeavours.

[2][4] Tabassian has also contributed to the Montreal Symphony Orchestra, the Nouvel Ensemble Moderne, Bradyworks, and the European Broadcasting Union.

[4] In 2017, as part of Montreal's 375th anniversary, Tabassian composed the anthem Mémoires d'Ahuntsic, which was presented as a gift to Ahuntsic.

[9] In 2020, Tabassian co-authored, alongside poet Hélène Dorion, the musical and poetic suite "Le temps des forêts", based on life stories collected from residents of LTCHs in Montreal.