Partch's title And on the Seventh Day Petals Fell in Petaluma pays homage to his native California. The composer spent 4 decades in the Bay of San Francisco, with 2 6-year breaks, always searching for new sound experiments. The 23 duet studies can be combined into larger-scale chamber music works and are also suitable as concert pieces - full of original polyrhythmics, polymetry and polytonality.