A device placed between a sound source and a microphone to trap wind blasts - such as those created by a vocalist’s plosives (Bs, Ps and so on) - which would otherwise cause loud popping noises as the microphone diaphragm is over- driven. Most are constructed from multiple layers of a fine wire or nylon mesh, although more modern designs tend to use open-cell foam.

A synthesizer that can play/sound more than one note at a time (eg. eight or 16 notes), each with an independent signal chain of oscillators, filters, and envelope generators.

The most common MIDI mode that allows an instrument to respond to multiple simultaneous notes transmitted on a single MIDI channel.

The ability of an instrument to play two or more notes simultaneously. An instrument which can only play one note at a time is described as monophonic.

This refers to a signal's voltage above or below the median line. Inverting the polarity of a signal swaps the positive voltage to negative voltage and vice versa. This condition is often referred to (incorrectly) as 'out-of-phase'.

The directional characteristic of a microphone (omni, cardioid, figure-eight, etc).

Consumer recorders, such as MP3 recorders, are often equipped with a microphone powering system called ‘Plug-In Power’. This operates with a much lower voltage (typically 1.5V) and is not compatible with phantom-powered mics at all.

A self-contained software signal processor, such as an Equaliser or Compressor, which can be ‘inserted’ into the notional signal path of a DAW. Plug-ins are available in a myriad of different forms and functions, and produced by the DAW manufacturers or third-party developers. Most plug-ins run natively on the computer’s processor, but some require bespoke DSP hardware. The VST format is the most common cross-platform plug-in format, although there are several others.

A device for changing the pitch of an audio signal without changing its duration.

A special control message specifically designed to produce a change in pitch in response to the movement of a pitch bend wheel or lever. Pitch bend data can be recorded and edited, just like any other MIDI controller data, even though it isn't part of the Controller message group.