Keshishian teaches at the Lebanese National Higher Conservatory of Music, he is a professor at the Parsegh Ganatchian Musical College and lecturer at Haigazian University. He is also the Artistic Director and Conductor of the Varanda Children's and Junior Youth Choir in Shushi, as well as the Gargatch Children's Juvenile Choir and the Ayc Youth Choir and folk orchestra in Beirut.