Osvaldo Golijov (b. 1960) composed Ayre, a song cycle for soprano and large ensemble, in 2004. On the larger thematic level, it explores the history of the conflicts among Christians, Jews, and Muslims—as well as their similarities—to reflect more broadly on the contemporary relationship between Israel and Palestine. To accomplish his goal, Golijov utilizes folk music and poetry from Andalusia, Morocco, Sardinia, and Lebanon as well as poetry by Mahmoud Darwish, a Palestinian poet. Golijov also interweaves the unique talents of specific musicians into the score, which thus becomes a vehicle to showcase the virtuosity of soprano Dawn Upshaw, who premiered and recorded the work, and Golijov’s hand-selected ensemble of instrumentalists, known as the Andalucian Dogs. Like Luciano Berio’s Folk Songs (1964), which served as Golijov’s model, Ayre is constructed using significant amounts of preexisting material. In addition, it incorporates substantial contributions from its original performers. This study examines Golijov’s own contributions and those provided by others to identify more clearly Golijov’s role as composer. It also places Golijov’s work in the broad historical context of twentieth-century music, taking into account the unique relationship between the composer and performer in the world of jazz and the many classical composers who have incorporated elements of folk and popular music into their art music. Additionally, it examines the music of select classical and popular composers—Béla Bartók, Igor Stravinsky, Aaron Copland, Duke Ellington, George Gershwin, and Gil Evans—to understand the censure that has often accompanied the appropriation of music from outside one’s normative style. The study concludes that Golijov, like many other postmodern composers, is not composing in reaction to the complexity and intellectualism of mid-century modernism, but rather he is composing in the manner of composers from the past who reverentially appropriated materials from a wide variety of musical traditions. Thus, even though Golijov relies on a significant amount of pre-existing material to construct Ayre, the work is ultimately a result of his own creative energy.