Abstract: A system for converting musical sounds into digital data for use with a electronic synthesizer. An infra red pitch sensor detects pitch of string vibration. Envelope of this signal is filtered and applied to a comparator with floating threshold. Square wave output of comparator is used to reset a continually running counter and latch valid data into a latch. Valid data is used as address for a memory which contains quantized values corresponding to standard musical notes. Transposition of keys may be accomplished in memory lookup table. Amplitude of input signal is detected by A/D converter, and with pitch information from memory lookup table is sent to processor. Processor makes decision when valid data is present, and when present outputs data to synthesizer.