Reference

The glossary

Every bit of jargon that turns up on a keyboard, controller, synth, pedal or stand spec sheet, explained once, properly. 120 terms.

These definitions also appear inline across the site: anywhere a term is highlighted, hover it to read the definition without leaving the page.

Basics

MIDIalso: MIDI controller, MIDI controllers: Musical Instrument Digital Interface, the 1983 standard for sending notes, knob movements and timing between instruments and computers. A MIDI controller makes no sound of its own; it sends MIDI to software or hardware that does.
MIDI 2.0also: Property Exchange: The 2020 update to MIDI: two-way communication, far higher resolution for velocity and controllers, and Property Exchange so a controller can ask a synth or DAW what its parameters are and label its knobs automatically.
DAWalso: DAWs: Digital Audio Workstation, recording and production software such as Ableton Live, Logic Pro, FL Studio or Cubase. Most controllers ship with scripts that map their controls to popular DAWs.
DAW transportalso: transport: Dedicated play, stop, record and loop buttons that drive your DAW, so you can punch in without reaching for the mouse.
HUI: Human User Interface, an old Mackie control-surface protocol that almost every DAW still understands. Controllers fall back to it for DAWs they have no custom script for.
list pricealso: RRP, MSRP: The manufacturer's published recommended price (RRP in the UK, MSRP in the US). Shops usually sell for less, and it excludes any tax or shipping differences between regions.
MIDI CCalso: CC, CCs, control change: Control Change, the MIDI message a knob, fader or pedal sends: a controller number (0 to 127) plus a value. Mod wheel is CC 1, sustain is CC 64; most other numbers are yours to assign.
program changealso: program changes, Program change: A MIDI message that tells a synth or plug-in to switch to another patch. Handy for changing sounds between songs from a controller or footswitch.

Keys

keybed: The mechanical keyboard assembly itself, the keys, their pivots and the sensors under them. Two controllers with the same key count can feel completely different because of the keybed.
synth-actionalso: synth action, synth-style: Light, springy keys with no added weight, fast for synth lines and drums, less piano-like. The most common action on controllers under 61 keys.
semi-weightedalso: semi weighted: Synth-style keys with extra weighting or damping so they feel a little more substantial than plain synth-action, without the full mechanics of a piano action.
FSBalso: Future System Basic, FSB keybed: Future System Basic, Yamaha's semi-weighted synth keybed, used on the MODX M6 and M7 and the CK61. The resistance is even across the keys and it is built for speed rather than piano weight, but it feels more solid than the lighter keys on earlier MODX models.
hammer-actionalso: hammer action, fully weighted, graded hammer: A piano-style mechanism with small hammers that give the keys real inertia. "Graded" means heavier in the bass and lighter in the treble, like an acoustic piano.
full-size keysalso: full size, Full: Keys the same width as a piano's (about 23.5 mm per white key). Most 49-key-and-up controllers use them.
mini keysalso: mini-keys, mini key, Mini: Narrower keys (roughly 80% of piano width) that let a 25- or 37-key controller fit in a laptop bag. Fine for melodies and bass; awkward for two-handed piano playing.
slim keysalso: Slim: In-between keys (full length but slightly narrower than piano keys) used on some compact synths and controllers.
velocityalso: velocity-sensitive, velocity sensitive: How hard you hit a key or pad, measured by how fast it travels. Nearly every controller sends velocity; the quality of the curve is what varies.
aftertouch: Pressure applied to a key after it's already down, sent as a continuous control. Great for adding vibrato or swelling a filter while holding a note.
channel aftertouchalso: Channel: The common kind of aftertouch: one pressure value for the whole keyboard, so pressing harder on any key affects every note that's sounding.
polyphonic aftertouchalso: poly aftertouch, poly-aftertouch, poly AT, Polyphonic: Aftertouch measured separately for each key (or pad), so you can lean into one note of a chord without affecting the others. Still rare on keyboards, common on pad grids.
MPEalso: MPE surface: MIDI Polyphonic Expression, a way of using MIDI so each note gets its own pitch bend, pressure and slide. It's what lets the ROLI Seaboard bend individual notes. Needs an MPE-aware synth.
octave buttonsalso: octave up/down, octave range: Shift the whole keyboard up or down in octaves so a small controller can still reach the full note range.
zones / splitsalso: zones, split, layer, Zones / splits: Dividing the keyboard so different ranges (splits) or the same range (layers) play different sounds or MIDI channels, bass in the left hand, piano in the right.
waterfall keysalso: waterfall, Waterfall, waterfall keyboard, waterfall manual, waterfall manuals, square-front: Organ-style keys with a flat, squared-off front edge and no overhanging lip, as on a Hammond B-3. The rounded shape lets you slide your hand off the front for glissandos and palm smears without catching an edge. Usually a light, fast synth-style action rather than weighted.
triple sensoralso: triple sensors, Triple Sensor, three-sensor: A hammer action that reads each key at three points instead of two, so fast repeated notes register even when the key hasn't fully risen, much like a real grand piano. Mostly found on stage and digital pianos.
escapementalso: let-off, let off: The slight notch you feel near the bottom of a grand piano key when you press it slowly, where the hammer lets go of the string. Some weighted keybeds imitate it so pianists feel at home; it makes no difference to the sound.

Controls

padsalso: pad, drum pads, pad grid: Rubber squares for finger drumming or launching clips, usually velocity-sensitive and often pressure-sensitive with RGB backlighting. 8 or 16 pads on keyboards; 64 on grid controllers.
clip launchingalso: clip launch, clip-launch, Session View: Triggering loops and scenes from a grid, Ableton Live Session View style. Grid controllers like the Launchpad and APC exist mainly for this.
fadersalso: fader: Sliders, typically nine (eight tracks plus a master) mapped to mixer levels or drawbars. 60 mm is the usual travel on controllers.
knobsalso: knob, potentiometers, pots: Rotary controls with a fixed start and end (about 270° of travel). Cheap and direct, but the position may not match the software value when you switch presets.
encodersalso: endless encoders, endless rotary encoders, encoder, Knobs / encoders: Knobs that turn forever. Because they send relative "up a bit / down a bit" messages, they never jump the software value. Ideal for DAW and plug-in control.
pitch bendalso: pitch wheel, Pitch / mod, pitch and mod wheels, Wheels: A spring-loaded wheel (or strip, joystick or lever) that bends the pitch of held notes up or down. Usually paired with a modulation wheel.
mod wheelalso: modulation wheel, modulation: A free-moving wheel that sends a continuous control, conventionally vibrato depth, but assignable to anything.
touch stripsalso: touch strip, Touch strips: Flat capacitive ribbons standing in for pitch and mod wheels on slim controllers. Lighter and cheaper, with less tactile feedback.
joystickalso: Joystick, thumb joystick: A single stick doing pitch bend on one axis and modulation on the other. Saves space on mini controllers.
arpeggiatoralso: arpeggio, arp: Holds a chord and plays its notes one at a time in a pattern, synced to tempo. Handy for instant rhythmic parts.
sequenceralso: step sequencer: Records and plays back a pattern of notes from the controller itself, useful for driving hardware synths without a computer.
scale modealso: Scale mode, scale-locked: Restricts the keys or pads to a chosen scale so every note you hit is "in key". A safety net, or a way to play melodically on a pad grid.
chord modealso: Chord mode, fixed chord, chord map: Plays a full chord from a single key or pad, either a fixed voicing you set, or chords chosen to fit the selected scale.
note repeatalso: Note repeat: Holding a pad retriggers it in time with the tempo (8ths, 16ths, triplets…). The MPC trick for hi-hat rolls and trap hats.
displayalso: OLED, LCD, screen, Colour LCD: Screen for parameter names and values. OLED is the small monochrome panel on most mid-range controllers; a colour LCD shows more but costs more.
Hall-effectalso: Hall effect, Hall-effect switches, Hall-effect keys, Hall-effect buttons: A contactless way of sensing movement: a magnet sits on the moving part and a sensor reads the strength of its field, so nothing rubs and nothing wears out. Because the sensor reports how far something has travelled rather than just whether it has been pressed, a Hall-effect button or key can send continuous pressure or position as well as a note, and it will not develop the crackle or dead spots that eventually affect mechanical contacts and carbon-track faders.
motorised knobsalso: motorized knobs, Motorised knobs, motorised: Knobs driven by small motors, so they physically turn to match the loaded patch or DAW parameter. What you see is always what you hear, with no value jumps when you touch them.
jog wheelalso: jog wheels, Jog wheel, Metal jog wheels: A large endless dial for scrubbing through audio or scrolling long lists, borrowed from DJ decks and video editors.
detentalso: centre detent, centre-detent, Centre-detent option, Detent or smooth: A small click or notch you can feel as a knob or fader turns. A centre detent marks the middle (useful for pan or EQ); stepped encoders click at every increment.
long-throw fadersalso: long-throw fader, Long-throw faders: Faders with longer travel (usually 100 mm) than the 45 to 60 mm ones on most controllers, giving finer control for mixing.
D-Beam: Roland's infrared sensor: wave your hand above it to control a parameter without touching anything.

Connectivity

USBalso: USB-C, USB-B, Micro-USB: The cable to your computer, carrying MIDI and usually power. USB-C is current; USB-B (the square printer plug) and Micro-USB are older but work identically with the right cable.
bus poweredalso: USB bus powered, bus-powered, USB-powered: Runs entirely from the USB cable, no power supply needed. Big 88-key boards or anything with a bright screen may need a wall adapter.
DIN MIDIalso: 5-pin MIDI, 5-pin DIN, DIN out, DIN in, MIDI ports, MIDI out, MIDI in: The classic round 5-pin MIDI socket. Lets a controller talk to hardware synths directly, with no computer in the chain.
TRS MIDIalso: TRS out, TRS in, 3.5mm MIDI, minijack MIDI: MIDI over a 3.5 mm headphone-style jack, used where a 5-pin socket won't fit. Needs a TRS-to-DIN adapter (Type A is the standard) to reach older gear.
CV / Gatealso: CV/Gate, CV/gate, CV / Gate out: Analogue control voltages for modular and vintage synths: CV sets pitch, Gate says when a note is on. A controller with CV/Gate outs can play a Eurorack system directly.
Bluetooth MIDIalso: Bluetooth, wireless MIDI, BLE MIDI, Apple BLE MIDI: Wireless MIDI to an iPad, Mac or PC. Latency is a few milliseconds higher than USB, fine for most playing, and it frees you from the cable.
sustain pedalalso: Sustain, sustain input: A ¼" jack for a piano-style on/off foot pedal that holds notes after you release the keys.
expression pedalalso: Expression: A ¼" jack for a continuous (rocking) foot pedal, volume swells, wah, or any parameter you assign.
footswitchalso: Footswitch: A generic on/off pedal input, assignable to things like start/stop or patch change rather than sustain.
audio interfacealso: Audio interface, built-in audio interface: Audio in/out built into the controller, so it can also be your soundcard. Record a mic or synth and monitor through it.
standalone modealso: Standalone mode, standalone: The controller does something useful with no computer attached, sequencing hardware, or in Push 3 Standalone's case running Ableton Live itself.
NKS: Native Kontrol Standard. Native Instruments' format that lets a controller browse plug-in presets and pre-map their knobs. Supported by most major plug-in makers.
Light Guide: The strip of LEDs above the keys on NI Kontrol keyboards showing scales, drum-kit zones and key splits in colour.
MIDI thrualso: DIN thru, thru, MIDI thru box, thru box: A socket that passes on an exact copy of whatever arrives at MIDI in, so several instruments can be chained from one source. A thru box does the same with many outputs.
MIDI mergealso: merge, Merges USB and DIN: Combining two or more MIDI streams into one, for example a keyboard and a pedalboard both playing the same synth.
MIDI clockalso: clock, sync, Sync in/out, analogue sync: A stream of timing pulses (24 per beat) that keeps sequencers, arpeggiators and drum machines playing at the same tempo. Sync in/out sockets carry clock, sometimes as an analogue pulse.
class compliantalso: class-compliant, Class compliant, Class-compliant, driverless: A USB device that works using the drivers already built into macOS, Windows, iOS and Linux, so there's nothing to install. Needed for USB host adaptors and iPads.
USB hostalso: USB-A host, USB MIDI host, USB host adaptor, USB host adaptors: The USB side that powers and controls other devices, normally a computer. A USB host adaptor stands in for the computer, so a USB-only controller can play hardware synths directly.
latencyalso: Latency, low latency: The delay between playing a note and hearing it. Under about 10 ms feels instant; wireless MIDI adds a few milliseconds, audio buffers in software usually add more.

Synths

analogue synthalso: analogue synths, analog synth, analog synths, analogue polysynth: A synth whose sound is generated and shaped by real electronic circuits (oscillators, filters, amplifiers) rather than code. Prized for warmth and slight instability; usually fewer voices and no patch morphing tricks without digital help.
virtual analoguealso: virtual analog, VA: A digital synth that models analogue circuits in software. Cheaper, lighter and more polyphonic than the real thing, and it stays in tune.
FM synthesisalso: FM, digital FM, frequency modulation, FM synth: Frequency modulation: one oscillator wobbles the pitch of another at audio speed, creating complex, bell-like and metallic tones. Made famous by the Yamaha DX7; almost always digital, hence 'digital FM'.
wavetablealso: wavetables, wavetable synthesis, wavetable synth: A digital oscillator that holds a set of single-cycle waveforms and sweeps between them, so the tone can morph continuously as you turn a knob or apply modulation.
hybrid synthalso: hybrid synths, Hybrid (digital oscillators, analogue filters): A synth that mixes digital and analogue stages, typically digital oscillators (wavetable, FM, samples) feeding a real analogue filter and amplifier.
sample-basedalso: sample playback, rompler, romplers: A sound engine that plays back recordings of real instruments rather than generating waveforms. Most multi-function keyboards work this way; the old nickname is 'rompler'.
physical modellingalso: physical modeling, physically modelled: A digital engine that simulates the physics of a real instrument (a vibrating string, a piano hammer, a blown pipe) instead of playing recordings. Responds very naturally to how you play.
granular synthesisalso: granular: Chopping a sample into tiny grains and replaying them layered, stretched or scattered. Great for pads, textures and time-stretching.
oscillatoralso: oscillators, Oscillators, VCO, VCOs, DCO, DCOs: The part of a synth that generates the raw tone. VCO is an analogue voltage-controlled oscillator; DCO is an analogue oscillator kept in tune digitally.
filter (VCF)also: VCF, ladder filter, transistor ladder, low-pass filter, 4-pole: Removes or emphasises frequencies to shape a synth's tone, usually a low-pass that makes the sound darker as it closes. A 4-pole ladder filter is the classic fat Moog design.
VCAalso: VCAs, Stereo VCA: Voltage-controlled amplifier: the stage that sets each note's volume, normally shaped by an envelope. A stereo VCA can pan voices across the stereo field.
envelopealso: envelopes, ADSR: A shape that changes a sound over the length of a note, usually ADSR: attack (fade in), decay, sustain (level while held) and release (fade after you let go).
LFOalso: LFOs: Low-frequency oscillator: a slow, inaudible wave used to modulate something else, such as pitch for vibrato or filter for a wobble.
polyphonyalso: voices, Voices, polysynth, polysynths, monophonic, paraphonic, mono synth: How many notes a synth can play at once, counted in voices. Monophonic means one note at a time (classic for bass and leads); paraphonic means several pitches sharing a single filter and envelope.
multi-timbralalso: multitimbral, Multi-timbral parts, bi-timbral, Bi-timbral, 4-part multi-timbral: Able to play several different patches at the same time, each on its own MIDI channel or keyboard zone. Bi-timbral means two parts.
patchalso: patches, preset, presets, Patch morphing: A saved sound: every setting on the synth stored so it can be recalled. Preset means the same thing, usually one supplied by the maker. Patch morphing glides smoothly from one patch to another.
desktop modulealso: Desktop module, sound module, sound modules: A synth with no keyboard, meant to sit on a desk or in a rack and be played from a MIDI controller. Cheaper and more portable than the keyboard version.
Eurorack: The most popular modular synth format: small modules in a shared case, patched together with 3.5 mm cables carrying CV and audio.

Organs

drawbarsalso: drawbar, pedal drawbars, LED drawbars: The sliders on a tonewheel organ that mix the harmonics, each one a different pitch (16', 8', 5⅓' and so on) pulled out to make it louder. Nine per manual is the Hammond standard. Physical drawbars let you sweep them live; some clones use buttons with LED ladders instead.
tonewheelalso: tonewheels, tonewheel organ, digital tonewheels, clonewheel, clonewheels: The spinning metal wheels inside a Hammond organ that generate each pitch, and the sound that comes with them. A clonewheel is a digital organ that models those wheels, including their quirks such as key click and leakage.
manualsalso: dual manual, Dual manual, upper manual, lower manual, single manual: An organ's keyboards. A dual-manual organ has two stacked keyboards (upper and lower), each with its own drawbar registration, so you can play a lead and a pad without switching sounds.
rotary speakeralso: rotary speakers, Leslie, Leslie speaker, Digital Leslie, rotary speaker simulation, rotary simulation: A speaker cabinet with a spinning horn on top and a spinning drum below, best known as the Leslie. The rotation adds the swirling Doppler movement heard on almost every rock and gospel organ record. Most organ keyboards include a digital simulation.
rotor speedalso: Rotor speed, roto speed, Roto speed, rotary speed, Leslie switch, Organ Leslie switch, half-moon switch, slow/fast, chorale/tremolo: The slow/fast switch for a rotary speaker (chorale and tremolo on a real Leslie). Players flip it mid-phrase, so the ramp as the rotors speed up or slow down is part of the sound. It's often a half-moon switch on the keyboard or a footswitch assigned to Rotor speed.
11-pin Lesliealso: Leslie 11-pin, 11-pin Leslie connector, 11-pin: The multi-pin socket that connects an organ to a real Leslie cabinet, carrying audio, power and the rotor speed control in one cable. Only matters if you plan to use a physical rotary speaker rather than the built-in simulation.
key clickalso: key-click, Key click, leakage, tonewheel leakage: The short percussive pop at the start of each note on a tonewheel organ, originally an electrical flaw that players came to love. Leakage is its cousin: the faint bleed of neighbouring tonewheels under every note. Good clonewheels let you set how much of each you hear.
organ percussionalso: harmonic percussion: A Hammond feature that adds a quickly decaying 2nd or 3rd harmonic to the start of each note for a bright, plucky attack. It only retriggers once all keys are released, which shapes how jazz organists phrase.
vibrato / chorusalso: vibrato/chorus, chorus/vibrato, scanner vibrato, C3 chorus, V/C: The Hammond scanner effect with six settings, V1–V3 for pitch vibrato and C1–C3 for chorus (vibrato mixed with the dry sound). C3 is the classic gospel and rock setting.
seamless transitionsalso: Seamless transitions, Seamless sound switching, seamless switching: Changing to a new sound or program without cutting off notes you are still holding or sustaining, so reverb tails and held chords ring on through the switch. Essential for live keyboard players changing sounds mid-song.

Pedals

half-damperalso: half damper, Half-damper, half-pedalling, continuous sensor, Continuous sensor: A sustain pedal with a continuous sensor instead of an on/off switch, so a keyboard that supports it can hold notes partially, as on an acoustic piano.
polarityalso: polarity switch, Polarity switch, normally open, normally closed, Normally closed: Whether a pedal's switch is open or closed at rest. Brands disagree (Yamaha and Korg expect normally open; Roland and Casio normally closed), so the wrong pedal works backwards. A polarity switch fixes it.
TS / TRS jackalso: 1/4" TS, 1/4" TRS, TRS socket, TRS jack, TS jack, ¼" jack: The ¼" (6.35 mm) plugs pedals use. TS has two contacts and suits simple on/off switches; TRS has three and is needed for expression pedals, half-damper pedals and dual footswitches on one cable.
piano-style pedalalso: piano-style sustain pedal, piano-style sustain pedals, piano-style pedals, Box switch, box switch: A sustain pedal shaped like the metal pedal on an acoustic piano, heavier and less likely to slide than a small box switch.
volume pedalalso: volume pedals, Volume pedal: A rocking pedal that controls level. On keyboards it's usually an expression pedal assigned to volume; some are passive and sit in the audio path.
triple pedalalso: triple pedals, 3-pedal unit, Triple pedal included, sostenuto, soft pedal: A three-pedal unit copying a grand piano: sustain (right), sostenuto (middle, holds only the notes already down) and soft or una corda (left).
organ swellalso: Organ swell, swell pedal, swell pedals, expression swell: An expression pedal used to control organ volume, the way a real organ's swell pedal does. Organists ride it constantly to push chords forward and pull them back. Many stage keyboards have a dedicated Organ swell input that only affects the organ section.

Stands

X-framealso: X-frames, X-stand, X-stands, X-frame stand: The classic folding keyboard stand shaped like an X from the side. Cheap, light and quick to set up; the cross-bars can get in the way of your knees and pedals.
Z-framealso: Z-frames, Z-stand, Z-stands: A stand with a Z-shaped side profile, leaving the space in front of your legs clear. Sturdier than an X-frame and easy to add tiers to.
A-framealso: A-frames, A-frame rack, A-frame racks: A tall stand shaped like an A with arms on both sides, holding several keyboards stacked at different heights. The go-to for multi-keyboard rigs.
column standalso: column stands, Column: A single upright column with arms mounted on it, usually on a heavy base. Very stable and tidy; less portable than an X-frame.
table standalso: table stands, Table: A four-legged table-shaped stand, the steadiest option and the easiest for sitting at with pedals.
bracingalso: Bracing, single-braced, double-braced, single braced, double braced: The tubes that form each side of an X-frame stand. Single-braced uses one tube per side; double-braced uses two, roughly doubling the load rating and cutting wobble.
tieralso: tiers, Tiers, second tier, Second tier, two-tier, three-tier: A level on a keyboard stand. A second tier holds another keyboard, usually angled above the first; many stands take a tier add-on sold separately.

Software

plug-in formatsalso: plug-in, plug-ins, plugin, plugins, Plug-in formats, VST, VST2, VST3, AU, Audio Units, CLAP, AAX: The standards that let instruments and effects load into a host: VST3 (Windows and Mac), AU (Mac only, needed for Logic and MainStage), CLAP (a newer open format) and AAX (Pro Tools only).
softsynthalso: softsynths, software synth, software synths, software instrument, software instruments: A synthesiser that is a program rather than a box: it runs inside a DAW or live host as a plug-in (or on its own as a standalone app) and is played from a MIDI keyboard. Many recreate classic hardware, such as Arturia's V Collection, for a fraction of the price of the original.
live hostalso: live hosts, plug-in host: Software built for playing plug-ins on stage rather than recording, such as MainStage and Gig Performer®: instant patch changes, no gaps in sound and set lists.
set listalso: set lists, Set lists, setlist, setlists: The running order of songs in a live host, each recalling its own sounds and controller mappings so one button press moves on to the next song.
rackspacealso: rackspaces: Gig Performer®'s name for a saved setup of plug-ins and controller mappings, like a patch for a whole rig. Variations change settings without reloading.
OSCalso: Open Sound Control, OSC control: Open Sound Control, a network protocol like MIDI with higher resolution and readable names, used for control from phone and tablet apps over Wi-Fi.

Guitars

humbuckeralso: humbuckers, HH, HSH: A guitar pickup with two coils wired to cancel hum. Thicker, louder and warmer than a single-coil; shown as H in layouts like HH or HSH.
single-coilalso: single-coils, single coil, SSS: A pickup with one coil: bright and clear but prone to hum. The Strat sound; shown as S in layouts like SSS.
coil splitalso: Coil split, coil splitting, coil tap: A switch (often a push-pull knob) that turns a humbucker into a single-coil for a brighter tone.
scale lengthalso: Scale length: The vibrating string length from nut to bridge. Longer (25.5", Fender) feels tighter and brighter; shorter (24.75", Gibson) is slinkier and warmer.
tremolo bridgealso: tremolo, Locking tremolo, locking tremolo, 2-point tremolo, Tune-o-matic, locking nut, Locking nut: A bridge with a bar that bends every string's pitch. A locking tremolo clamps the strings at the nut (a locking nut) and bridge to stay in tune after heavy use; a Tune-o-matic is a fixed bridge.
neck profilealso: Neck profile: The shape of the back of the neck in cross-section, such as C, D or thin. Affects comfort more than almost any other spec.