Glass Cathedral was commissioned by Rela Percussion with the intention of being performed on four glass marimbas. After hearing recordings of this particular instrument as well as videos and pictures, I thought immediately of the famous “Crystal Cathedral” in Garden Grove, California. The structure is made of steel with over 12,000 panes of glass and houses one of the largest pipe organs in the world and has been a perfect venue for large choirs and orchestras. Hence, Glass Cathedral seeks to reflect such a magnificent structure and performance venue by using “glittering” passages of the glass marimbas against slow and sustained organ and chant-like lines.
The work starts in G-flat Lydian mode with sixteenths against triplet eighths in the upper two marimbas and continues, almost in perpetual motion, throughout the entire piece, usually in the upper voices. Against this sonic landscape the first organ-like theme is heard in the lower two marimbas. Following, the lower marimbas work the theme antiphonally against continuous sixteenths in the upper instruments. This modulates to B-flat Lydian and the upper instruments present the theme in octaves (chant-like) accompanied by sweeping arpeggiated chords in the lower instruments. A transitional/developmental section follows in D Mixolydian mode in six-sixteen meter and modulates to F major. The lower instruments now present a second theme, hymn-like in nature, alluding to a choir and organ. The upper instruments accompany in sextuplets. This segues to A major where the lower and upper instruments play the second theme aniphonally and lead to a return of the first theme in the lowest marimba against a ostinato of sextuplets in the upper voices. Following, the upper two marimbas return to the original “glittering” pattern (sixteenths against triplet eighths) and the lower two marimbas play an organ-like passage that tonicizes C major, E-flat minor, F-sharp minor, F major and return to A major where the entire ensemble, in “tour-de-force” fashion, plays the second theme and modulates back to the coda in G-flat major. The coda consists of a pedal G-flat major chord sustained by the highest marimba against descending sixteenths (glitter) in the lower instruments, leading to a quiet and peaceful ending.