Quantization

The division of a continuous event (such as an analog signal) into a series of discrete steps. To quantize or quantify something. In digital audio recording this takes the form of “sampling” (another word for quantizing) the analog signal a specified number of times per second (sampling rate) with each sample made up of some known amount of information (how many bits, or bit depth – i.e. 16-bit, 24-bit, etc.). In MIDI it pertains to the timing resolution of a sequencer or drum machine and is measured in Pulses Per Quarter Note (PPQN). For example, a 480 PPQN sequencer has greater timing resolution than a 96 PPQN sequencer. Also in MIDI the verb quantize means to perform an operation to the MIDI data that will bring notes closer to a specified grid of acceptable timing values. For example, you could quantize a performance where someone played inconsistently to make all of their note events land on even quarter notes. Over-quantization results when such correction is so extreme that the resulting sequence becomes stiff or robotic sounding.