Morten Johannes Lauridsen, Composer-in-Residence of the Los Angeles Master Chorale from 1994-2001 and Professor of Composition at the University of Southern California Thornton School of Music for more than thirty years, occupies a permanent place in the standard vocal repertoire of the twentieth century. His seven vocal cycles—Les chansons des roses (Rilke), Mid-Winter Songs (Graves), Cuatro Canciones (Lorca), A Winter Come (Moss), Madrigali: Six 'FireSongs' on Renaissance Italian Poems, Nocturnes, and Lux aeterna—and his series of sacred a cappella motets (O magnum mysterium, Ave Maria, O nata lux, Ubi caritas et amor and Ave dulcissima Maria) are featured regularly in concert by distinguished ensembles throughout the world. O magnum mysterium, Dirait-on (from Les chansons des roses) and O nata lux (from Lux aeterna) have become the all-time best-selling choral octavos distributed by Theodore Presser, in business since 1783.

In speaking of Lauridsen's sacred works in his book, Choral music in the twentieth century, musicologist and conductor Nick Strimple describes Lauridsen as 'the only American composer in history who can be called a mystic, (whose) probing, serene work contains an elusive and indefinable ingredient which leaves the impression that all the questions have been answered …' From 1993 Lauridsen's music rapidly increased in international popularity, and by century's end he had eclipsed Randall Thompson as the most frequently performed American choral composer.