He plays mostly original compositions, strongly influenced by the Armenian folk tradition, often using its scales and modalities.

[4] He studied jazz from the age of nine, then tried to incorporate local folk melodies into jazz-form improvisations when in his teens.

[4] At this stage, Hamasyan was influenced by Armenian composers Arno Babajanian and Avet Terterian.

On April 29, 2022, Nonesuch Records released Hamasyan's first album of American standards - StandArt.

The project was recorded in the spring of 2021 in Los Angeles and includes 9 songs from the 1920s through the 1950s, by Richard Rodgers, Charlie Parker, Jerome Kern, David Raksin, and others.