A Breath Controller is a device that converts breath pressure into MIDI control data.

It is an accessory, usually with a mouthpiece, that the musician blows into while playing a keyboard or other MIDI instrument.

The force of the breath is measured and translated into control messages, allowing the musician to modulate the sound of a synthesizer in an expressive and organic way, similar to a real wind instrument.

It is widely used by keyboardists and wind instrument players to control parameters such as:

• Volume: Stronger breaths increase the volume, mimicking the dynamics of a saxophone or flute.

• Timbre Brightness: Can be mapped to the filter cutoff, making the sound brighter with more intense breaths.

• Modulation: Control the depth of a vibrato or other effects.