Morton Subotnick helped bring the modular voltage-controlled synthesizer to a state of readiness for performance and recording and was the first composer to take advantage of the new instrument's potential. Composed in 1967 specifically for release on Nonesuch, Silver Apples of the Moon was Subotnick's first full-length LP of electronic music, and the album became an international sensation. Its title is taken from Yeats' "The Song of Wandering Aengus," in which Subotnick found inspiration. Structured as a series of sonic plateaus and troughs, Part A has a fascinating vocabulary of points, glissandi, spatters, hisses, whistles, and sirens, and the variety of tones and gestures sustain interest. Yet, in contrast to the first part's capricious shapes and irregular sections, Part B develops rather predictable sequences over a steady ostinato, which seems automated and uninspired when compared to the fresh ideas heard earlier. In 1968, Subotnick released The Wild Bull, a dark work that relies on deep, lowing tones, harsh attacks, and metallic sonorities to convey its tragic mood. Inspired by an ancient Sumerian poem of mourning, Subotnick gave this piece a human quality by simulating cries and mixing in the sound of breathing. The original tapes were restored and digitally mastered in 1993 for Wergo's reissue on disc.