In Glass Sparks the image of fiery but fragile sparks being thrown out from a grinding metallic wheel is suggested by spinning motives, scraping timbres, and conflicting cross rhythms. Warped streaks of light from glowing embers tossed in all directions are reflected in the frequent bending of pitch and rapidly changing meters with syncopation that combine to create a sense of being off balance. A short section in the middle presents the image in slow motion, with notes seemingly melting away as they slide downward.