Learn / Glossary
The words,
A to Z
Every term used in the lessons and the instrument cards, in plain words. Twenty so far; the list grows with each lesson.
A
- Amplifier
- In a synthesizer, the stage that sets how loud the sound is; on analogue synths it is often called the VCA, the voltage-controlled amplifier. An envelope usually opens it each time a key is played and closes it after. The synthesizer →
B
- Balanced audio
- Sending a signal on two conductors plus a shield. Noise picked up equally on both conductors cancels at the receiver, which takes the difference between them. The full entry →
C
- Chord
- Three or more notes sounded together. The simplest is the triad. Lesson: what a chord is →
E
- Envelope
- A control that moves a setting once each time a key is pressed, usually in four stages: attack (how fast it rises), decay (how fast it falls back), sustain (the level it holds while the key is down) and release (how fast it fades after the key is let go). Often written ADSR.
F
- Fifth
- In a chord, the note four scale steps above the root. The perfect fifth is seven semitones up: from C, it is G. It gives the chord its body.
- Filter
- Removes part of a sound's frequency range. A low-pass filter lets the lows through and cuts the highs above its cutoff frequency; turning the cutoff down makes the sound darker.
I
- Interval
- The distance between two notes, counted in semitones or named by scale steps. A minor third is three semitones, a major third four, a perfect fifth seven and an octave twelve.
L
- LFO
- Low-frequency oscillator: an oscillator running too slowly to be heard as a note, used to move another setting up and down. On pitch it makes vibrato, on loudness tremolo, on a filter a slow sweep.
M
- Major chord
- A triad of a root, the note four semitones up (a major third) and the note seven up (a perfect fifth). C major is C, E and G.
- Minor chord
- A triad of a root, the note three semitones up (a minor third) and the note seven up (a perfect fifth). C minor is C, E♭ and G.
O
- Octave
- The interval of twelve semitones. The upper note vibrates at twice the frequency of the lower one, and the two share a letter name.
- Oscillator
- The part of a synthesizer that makes the raw, repeating wave: sine, triangle, sawtooth or square. How fast it repeats sets the pitch. The synthesizer →
P
- Phase
- Where a wave is in its cycle at a given moment, measured in degrees. Two identical waves half a cycle apart (180°) cancel when added; flipping a signal's polarity has the same effect on a simple wave, which is why the two ideas are often confused.
R
- Root
- The note a chord is built on and named after: the C in C major.
S
- Semitone
- The smallest step in Western music: from one key on a keyboard to the very next, black or white, or from one guitar fret to the next. Twelve make an octave. Also called a half step.
T
- Third
- In a chord, the note two scale steps above the root. Four semitones up is a major third, three a minor third; the third decides whether a chord is major or minor.
- Triad
- A chord of three notes stacked in thirds: a root, a third and a fifth.
- TRS
- Tip, ring, sleeve: a jack plug with three contacts, often ¼ inch (6.35 mm) across. It carries either one balanced signal (tip hot, ring cold, sleeve the shield) or two unbalanced ones, left and right, as on headphones. Cables & connectors →
U
- Unbalanced
- A connection with one signal conductor and a shield that also carries the return. Simple and fine over short runs, but noise picked up along the cable is not cancelled. A guitar cable with two-contact (TS) jacks is unbalanced.
X
- XLR
- A round, latching connector, usually with three pins, used for microphones and balanced line connections. The XLR connector →