Morten Lauridsen is one of the most prolific composers of choral music in the 20th and 21st centuries. His characteristic tone is both readily identifiable and timeless. Works such as Lux Aeterna, Les Chansons des Roses, “Sure on this Shining Night” (from Nocturnes) , and “O magnum mysterium” have solidified his place as one of the most important compositional voices in modern choral music. Lauridsen’s most often-performed choral works have been individual movements excerpted from his larger choral works, due to their accessibility for advanced high school and collegiate choirs. For example, the popular “Dirait-on” comes from the cycle Les Chansons des Roses; “O nata lux” from Lux Aeterna; and “Sure on this Shining Night” from Nocturnes. Although “Sure on this Shining Night” is performed across the United States on a variety of concert programs from high school to professional choirs, it is rare to encounter a performance of the choral cycle Nocturnes in its entirety. Morten Lauridsen composed Nocturnes as the Raymond W. Brock Commissioned Work for the 2005 American Choral Directors Association (ACDA) National Convention in Los Angeles. At the time of its composition, Nocturnes was a choral cycle consisting of three movements: “Sa Nuit d’Été,” “Soneto de la Noche,” and “Sure on this Shining Night.” Later, in 2008, he added a fourth piece, “Epilogue: Voici le Soir,” which would round out the cycle. Interesting elements of both unity and contrast weave through this choral cycle, potentially leaving the listener and performer to wonder what inspired Lauridsen to select the variety of languages, poetry, and instrumentation. Three different languages and poets are utilized throughout the cycle: “Sa nuit d’Été” in French, set to a poem by Rainer Maria Rilke, “Soneto de la Noche” in Spanish, set to a poem by Pablo Neruda, “Sure on this Shining Night” in English, set to a poem by James Agee, and “Epilogue: Voici le Soir returning to French and the poetry of Rilke. Another element of contrast exists in the instrumentation, with three out of the four pieces utilizing the piano. “Soneto de la Noche,” however, is a cappella with much more pervasive vocal divisi than the other pieces, making it the most technically difficult piece in the cycle. The variety of languages and difference in level of difficulty is one reason that this song cycle is not widely performed in its entirety. This monograph draws on background information regarding other similar works by Lauridsen, information regarding the poetry of these works, and musical analysis of these works, in addition to an interview with Lauridsen himself.