For the theater, he composed music for Anthony Kavanagh's One Man Show, as well as several songs for "Ma femme s'appelle Maurice" by Raffy Shart.

In 2001, Essaï landed the role of Count Paris in Gérard Presgurvic's musical comedy "Romeo and Juliet."

"[3] Essaï collaborated with Michel Legrand; together, they produced 25 songs for the 2003 musical adaptation of "Les Demoiselles de Rochefort."

[5] In 2015, Essaï released his song "Je n'oublie pas - Chem Morana,"[6] dedicated to the 1.5 million victims of the 1915 Armenian genocide on the 100th anniversary of its occurrence.

Essaï was one of the 6 members of Genealogy, the band representing Armenia at the Eurovision Song Contest in Vienna, Austria.

[7]In 2020, Essaï created the musical "Noé, la force de vivre," inspired by the story of Noah's Ark.

[9] In 2024, Essaï embarked on a tour to China to play his musical show NOÉ, la force de vivre in seven different cities.

He was accompanied by his entire troupe for this international tour, marking a significant milestone in bringing this work to audiences abroad.

[10][11] Essaï was a member of the supergroup Genealogy, who represented Armenia in the 60th Eurovision Song Contest held in Vienna.