In this study, the peşrev in Hüseynîaşîrân maqam, whose composer is unknown and notated by Cüneyd Kosal, is analyzed by comparing the same peşrev in Hüseynîaşîrân maqam, registered with the composer Isak, in the Collection of Muallim İsmail Hakkı Bey and Leon Hancıyan. In the study, all available copies of the work were brought together. It has been researched who the composer of the piece is. It has been concluded that Isak, who is registered as a composer in the copies in the Collection of Muallim İsmail Hakkı Bey and Leon Hancıyan, is actually Tanbûrî İsak. Notation systems in which accessible copies are written have been introduced. Information about the Hamparsum notation system is given. The copy in Muallim İsmail Hakkı Bey Collection, which is thought to be the oldest copy that can be reached, was converted from the Hamparsum notation system to the Arel-Ezgi-Uzdilek System and examined. The copies available in the study were compared by rewriting on the template. As a result of the comparison, it has been determined that there are differences between the copies in terms of tune, scale, pitch and transition. It has been determined that the copy in the Leon Hancıyan Collection is significantly different from other copies. As a result of the study, the change that the work undergoes on the way of meshk has been determined and revealed through the copies.