As a leader, Donelian has composed over 90-100 works and produced more than a dozen critically acclaimed albums for labels such as Sunnyside, Playscape, Odin, and Atlas, including "Stargazer," "A Reverie: Solo Piano," "Secrets," "Mystic Heights," "Full Moon Music," and "Oasis." His projects often explore Armenian and Middle Eastern themes, notably his work with reedman Souren Baronian on "Positively Armenian" and his role in Ara Dinkjian's group Night Ark, which blended jazz with Middle Eastern modalities. Critics have praised albums like "Leapfrog" for balancing compositional complexity with collective improvisational freedom, underscoring his reputation as a consummate modern jazz musician. Parallel to his performing career, Donelian is a prominent educator. Since the 1980s he has taught at The New School's jazz program and at William Paterson University, and he has given clinics and master classes worldwide, including work as a Fulbright Scholar in Armenia. He is the author of several influential pedagogy texts, notably "Training the Ear, Vol. 1," which has been published in multiple languages and used internationally in ear-training curricula. Through his playing, compositions, and teaching, Donelian occupies a distinctive place in contemporary jazz, uniting rigorous craft with cross-cultural musical insight.