Ēriks Ešenvalds is an early twenty-first century composer who has been commissioned to write works for some of the most noteworthy ensembles in the world. Having written over 100 compositions to date, 72 of which are choral pieces, Ešenvalds is quickly becoming one of the most prolific and significant composers of his time. He currently works as a full-time composer out of Riga, Latvia. Ešenvalds’s choral works are primarily unaccompanied, while some include brass band, saxophone quartet, percussion, or orchestral accompaniment. Textures vary from three to twelve voice parts. His oratorio Passion and Resurrection (2005), written for soprano solo, SATB quartet, SATB chorus, SS soli, and strings, is an amalgamation of compositional techniques drawn from all eras of music history. This project identifies characteristics of Roman Catholic and Byzantine chant that are imitated throughout Passion and Resurrection. A succinct history of both styles is presented along with a detailing of Ešenvalds’s compositional technique and an overview of his oratorio. Aspects of form, melody, text, rhythm, harmony, and texture present in each movement are also discussed. This study provides conductors with insight into the chant-like aspects of Ešenvalds’s work and any influences on performance. Listings of notable Passion settings and Ešenvalds’s choral output are also included.