The aim of the article is to look over and inspect one of the prominent representatives of diaspora Armenian music, Lebanese-Armenian composer, pianist, musicologist, pedagogue, and public figure Boghos Gelalian’s (1927–2011) series of the "Seven Sequences", written in 1966–67, considered the peak of the composer’s mature creativity and innovation. The "Seven Sequences" are composed for symphonic orchestra and are possible to be performed with a chamber ensemble as well. "Seven Sequences" were published by "Edition Peters" in Leipzig in 1971. Our task is to reveal the characteristics and the specialty of the musical language of the "Seven Sequences" series, as well as to present the overall performance history of the piece. Descriptive, analytic, and observatory-comparative methods are widely used throughout the research within the context of art studies. As a result of the analysis, it is recorded that the main thematic cell of the "Seven Sequences", with the integration of its unique and national subtle colors, has a significant dramatic sense, as the entire composition is built and based on it. Upon pursuing the performance history of the "Seven Sequences", the author found out that the premiere of the work took place in 1967 at the Assembly Hall of the American University of Beirut, performed by conductor Raif Abillalamah, to whom the composer has dedicated the "Seven Sequences". Years later, on May 4, 2012, the "Seven Sequences" were performed again in Beirut, this time by the Lebanese Philharmonic Orchestra, under the baton of conductor Harutyun Fazlian, during a special concert in honor of Lebanese composers at the UNESCO Palace. The "Seven Sequences" were performed in Armenia on January 12, 2014 at the IX Chamber Music Concert Series in Dilijan by a chamber ensemble conducted by Vatsche Barsoumian.