Zajal is the first opera, in three acts, created by Zad Moultaka, Lebanese composer living in Paris, who conducts a research in order to achieve a personal music language based on the integration of composition occidental techniques and oral tradition, belonging to the Arabic music. He chose the genre of the zajal, because of its importance as a form of literary verbal contest, spoken in dialect, still performed nowadays, in spite of its very ancient origins. The libretto is an extract from the Dīwān Šaḥrūr written by the contemporary Lebanese poet, Nabil el-Feghali. This contribution wants to study the expedients created by the composer and analyze the declinations about the notion of “graft” that he carries out in order to create an approach between his native music environment (Arabic music) and his spiritual adoptive one (contemporary occidental music). Zajal represents a fertile land to carry out cohabitation among different elements: the analysis of graft is inflected at many levels and has surprising results of originality and innovation.