Nonlinear Labs' first product - the C15 - is a polyphonic instrument based on digital sound synthesis. The purpose of the audio engine is not to model analog machines of the past or to play back samples or complex waveforms. Instead, we have chosen a puristic approach. Based on elementary mathematic algorithms, the signals are generated, modulated, shaped, and filtered in realtime. Therefore the sound can be dramatically influenced by the dynamic playing of a musician. As a pure player instrument, the C15 is built for human control.