Reduction, addition, then repeat, sort of. Composer, professor and early Internet enthusiast William Duckworth came to prominence with the third wave of Minimalist composers, a moment when musicians were moving beyond the perceived strictures of early Minimalism. His works and actions marked a change of direction, too. An indefatigable educator's demeanor and dissimilar proximity to comparable composers (he wasn't slugging it out in New York, but teaching at Pennsylvania's Bucknell University) may have kept him out of the internecine, proprietary beefs that plagued the various Minimalist schools.
Duckworth is often cited as popularizing the Postminimalist school, known for less recognizable modern idioms. His 24 Time Curve Preludes from 1977 and 1978 are luminescent piano works around a principal melody that jigger with the rhythm and tone centers via a series of formulas including additive and reductive techniques, drone studies, the strong left hand of boogie-woogie piano and bluegrass.
Like his piano preludes, the choral work of his early 1980s Southern Harmony continued to disrobe the most famous models of Minimalism. The shaped-note singing of Duckworth's churchgoing North Carolina youth, his studies at University of Illinois with microtonalist Ben Johnston, and Steve Reich's early, canon-influenced pieces Come Out and Piano Phase informed Southern Harmony's 20 unpredictable, all-vocal sections.
Modern-composition documentarist Alex Ross noted Postminimalists to be a plugged-in crowd. Duckworth and his wife, Nora Farrell, created 1997's Cathedral, a massive interactive web-based work weaving together live and virtual elements. Their multiplex 2.0 composition continued with 2009's Sonic Babylon, an invisible world of site-specific performance ("sound gardens") accessible by mobile devices.