Each movement of Four Passions relates a spiritual model to a scientific one. The spiritual model provides context for a musical experience and is either ceremonial (movements I and IV) or contemplative (movements II and III). The mathematical model primarily inspires the treatment of a texture; however, in some cases it may have a more direct impact on the music. The listener is not expected to hear a mathematical construct in the music (although, it is certainly fine to do so); the model is, however, chosen with respect to the corresponding spiritual model. The titles of the movements are foci for the intersections the spiritual and mathematical models-they are objects, images, or concepts that because of their vividness occur as passions.

The first movement, Cathedral, uses classical proportions (according to the golden ratio) for its formal structure. This applies recursively, i.e. the proportionality exists a the level of section, sub-section, phrase, etc. Certain musical markers emphasize these divisions-a long pause between the two largest sections, the recurrence of the bamboo chimes to delineate small sections, and so forth.

^{Percussion, Patti Cudd; Electronics, Nathaniel Tull Phillips}

The second movement, e, uses statistics (the title, e, refers to the well-known mathematical constant which figures into the formula for many statistical distributions) to determine when the percussionist should strike an instrument. The general effect is a slow rise and fall in density. For the tape part, I use material which has spectral characteristics related to a statistical distribution.

^{Percussion, Patti Cudd; Electronics, Nathaniel Tull Phillips}

The third movement, Chrysanthemum, has no direct correspondence to a mathematical model. However, the sound world is inspired by fractal-like processes. Recursion and ornamentation (visual features of fractal images) become the central focus for generating pitch and rhythmic material. (The title is meant to evoke the image of chrysanthemum, but more specifically relates to the chrysanthemum painting of Mondrain and comments about those paintings by Morton Feldman. The spiritual nature of FeldmanÃs music, which for me has certain Zen-like qualities, meshes well with the mathematical inspiration for this movement.)

^{Marimba, Patti Cudd}

The last movement, Vulcan Mosh Pit, uses ideas from chaos theory, particularly period doubling phenomena. Small perturbations in a fundamental line give rise to complex textures. The phrase structure resembles the path to chaos whereby bifurcations of a simple oscillation give rise to increasingly complex oscillations (period doubling). The music, however, reverses this progression-going from complex textures to simple ones.

^{Percussion, Patti Cudd; Electronics, Nathaniel Tull Phillips}

There are two prevailing themes threading through all four movements. One, as the work progresses the presence of electronics diminishes until the last movement where there is nothing but simple amplification. Two, downward trajectories regulate material within phrases. This occurs in a variety of guises: timbrally (movement II), pitch (movement I and III), or contrapuntally (movement IV, where the downward lines in pitch and timbre are simultaneously challenged by rising lines).