Jonathan D. Kramer, Postmodern Music, Postmodern Listening (Bloomsbury, 2016), Chapter 4:
Questioning, or even attacking, the previously all but unassailable barrier between pop and art music has energized postmodern music. Whereas there have certainly been modernist composers who enjoy vernacular music, only under the influence of postmodernism have art-music composers invited pop music into ostensibly art-music compositions. In the case of conservative postmodernists, the motivation may have been to reach out to an audience increasingly alienated from the world of serious concert music; in the case of radical postmodernists, the reason may have been to create unsettling and challenging contexts in which different styles confront each other. Despite the rhetoric of some composers and critics, most such crossover music does not cross completely freely from one musical world to another. Postmodernism thrives on otherness, on the recognition that something foreign is being embraced.
Footnote (no. 46) to the above passage:
John Rea offers a wonderfully varied list of postmodernist crossover music. Notice how, in most instances, the composer or performer’s stylistic or aesthetic affinity is on clearly one side of the divide, with foreign elements welcomed in precisely for their otherness, their exoticism: “Yehudi Menuhin playing ragas with Ravi Shankar or improvising hot jazz with Stéphane Grappelli; the Swingle Singers interpreting Bach by scat singing; the Beatles using a sitär in the Sergeant Pepper album; the settings of Folk Songs by Berio; Switched-on Bach for synthesizers, where the arranger/transcriber would change sex by the time he/she had completed the recording project; any one of the innumerable happenings organized by John Cage; the second movement of György Ligeti’s Three Pieces for Two Pianos entitled Selbstportrait mit Reich und Riley (und Chopin ist auch dabei); almost any ensemble in the Early Music movement that, in performing to extremely fast tempi, always leaves the impression that it might as well have played music to accompany a cartoon; jazz pianist Keith Jarrett performing Shostakovich or playing the harpsichord; the Kronos String Quartet, dressed in costume and exploiting rock-’n’-roll theatrical lighting, performing "Purple Haze" by Jimi Hendrix; the Koto Ensemble of Tokyo playing Vivaldi; Pavarotti singing with Dalla and Sting; the symphonies of Philip Glass; the Liverpool Oratorio by Paul McCartney; Itzahk Perlman playing klezmer music; Gidon Kremer playing tangos; the Shanghai Film Orchestra playing In C by Terry Riley on traditional Chinese instruments; the symphonies of Krzysztof Penderecki; Bobby McFerrin conducting and Chick Corea playing a Mozart piano concerto where the cadenzas are jazz-like improvisations; Belgian singer Helmut Lotti singing classical songs and arias but sounding like Mario Lanza’s operatic persona-manqué; American pop singer Neil Diamond singing the Hallelujah Chorus from Handel’s Messiah; jazz saxophonist Jan Garbarek playing in a church while the Hilliard Ensemble sings Lasso and Palestrina; the English pop music group Oasis, feebly copying the Beatles, including their haircuts; the celebratory Symphony 1997 -- Heaven, Earth, Mankind by Tan Dun, written to mark the transfer of power in Hong Kong from Great Britain to China; the very long symphonic poem, Standing Stone, by Sir Paul McCartney, which sounds as if it had been written by Rachmaninoff after having taken LSD; and, finally, cellist Yo-Yo Ma playing tangos,” John Rea, “Postmodernisms.”