Lux Aeterna (2018) by Christopher Mitchell

Lux Aeterna is my doctoral dissertation composition. The text, in its original Latin, is from the Requiem Mass. The pitch material for the four voices is directly derived from the original Gregorian Chant (B, C#, D, E, F#, G, A). The primary pitch materials for the instrumental ensemble are drawn from the overtone series, with the fundamental of B natural. As found in the natural overtone series, the chords produced in this composition include microtones found both naturally from the series along with microtones added by the composer to create harmonic friction. This treatment of microtonal materials is juxtaposed with the “pure” nature of the B minor modal scale sung by the 4 vocalists.
Lux Aeterna uses the performance space so that the sixteen performers and conductor surround the audience in an oval shape. Entrances of instruments are determined by their position around the audience and the way in which those sounds interact with one another across the space of the hall. The instruments are strategically placed so that timbres can be balanced in a specific way and the listener can hear the pitches blend in the acoustics of the hall. The goal is to create an immersive listening experience for the audience.
While composing this piece, which I started during my time in Boston and Spain last summer, I wanted to combine old musical elements with newer ones. I have always been interested in chant music and drones, and the way these sounds reverberate inside a large space, such as a cathedral. For many years I envisioned composing a sacred composition for choir and orchestra, and this finally was my opportunity to do so. The piece is inspired by darkness and light: not physically, but spiritually. Throughout the composition the darkness (the harmony in the instruments) is pitted against the light (the vocals). The struggle continues until the last section of the piece, when the opposing forces come out of the darkness and into the eternal light.