In 1995, a string quartet strapped into four helicopters played a synchronized score while rotor noise was mixed live and beamed to a concert hall. This episode explains the mind behind that spectacle, Karlheinz Stockhausen, born in 1928 near Cologne, whose mother was murdered at the Hadamar facility under the Nazi killing of the mentally ill, whose father went missing in action in 1945, and who served as a teenage stretcher bearer before rebuilding music from its atoms.

The hosts walk through the 1950s Cologne studio where Stockhausen generated sine waves, measured tape with a ruler, and spliced it with a razor blade; the spherical auditorium at the 1970 Osaka World’s Fair where seven rings of loudspeakers reached an estimated one million listeners; and the 29-year opera cycle Licht built from a single formula and cast with his own children. They also cover his influence on the Beatles, Miles Davis, and Bjork, protests from political radicals in the late 1960s, his claims of an education near the star Sirius, and the backlash over his comments after September 11.

• Treating pitch, duration, and volume as independent parameters, and splicing a boy’s voice with electronic tones
• Spatialization and variable form: orchestras in the corners of a room and scores read in any order
• Why a spherical hall with a sound-permeable platform anticipated spatial audio and VR
• Formula composition explained as a seed or fractal that dictates lighting cues and dancers’ movements
• The Helicopter String Quartet’s place in the Wednesday opera of Licht and the tension of a family ensemble built by an orphan of war