Concepts

Music theory you can play with, not just read. Pick an interactive concept to explore on the keyboard, or look up a term in the glossary. New to theory? Start with the Introduction to Music Theory guide.

Fundamentals

Notes & the KeyboardPress the keys to hear each note. See how every key maps to a pitch, and why the black keys carry two names.
Understanding Sound: Pitch and AmplitudeSound is a vibration. Sweep an oscillator across the audible range to hear how frequency makes pitch and amplitude makes loudness, and that the two are independent.
Musical NotesThe twelve notes are music's alphabet. Meet the seven natural letters and the five sharps and flats between them, and press each to hear and see where it lives.
Reading Music: The Stave & ClefsWhere notes live on the page. Meet the stave, the treble and bass clefs and the grand stave, and press a key to see its note appear - then read it back.
Reading Music: Note Values & RhythmHow long each note lasts. From semibreve to semiquaver, with rests, dots, ties and beams - hear the values played so the beat becomes something you feel.
Reading Music: Time Signatures & BarsHow beats group into bars. Read 4/4, 3/4 and 6/8, see the bar lines, and count the pulse with an accented downbeat you can hear.
Reading Music: Dynamics, Tempo & ArticulationThe marks that bring a score to life. Loudness (p and f), speed (tempo) and touch (staccato, legato) - hear one phrase change as each is applied.
KeysA key is the family of notes and chords a piece is built around: the same scale or chord shape played from any of the twelve roots, and why a composer chooses one key over another.

Harmony

IntervalsThe distance between two notes: the gap you hear and the vocabulary chords are built from. Play a pair to name it, or pick an interval to hear it.
ChordsStack notes and they become a chord. Press a chord to hear it, or play your own and have it named, and find out when a handful of notes is no chord at all.
ScalesPick a tonic and a scale type, the seven modes plus the minors, and play it up and down. See how each degree takes its own letter, and why melodic minor changes on the way home.
Key SignaturesThe sharps and flats that define a key, laid out on the circle of fifths and written on the staff. See why D major needs F♯ and C♯, and which minor shares each signature.
Chords in a KeyWhich chords belong to a key: the diatonic seven, with Roman numerals and functions. Play any chord and find out if it is the I, the V, or an outsider borrowed from elsewhere.

Key Terms

RootThe note a scale or chord is named from and measured against.
TonicThe note that feels like home in a key, and how it differs from the root.
DiatonicBelonging to the major scale and its modes: seven notes spread across the octave.
Harmony, Melody & RhythmThe three building blocks of music: notes stacked, notes in sequence, and notes in time.
Consonance & DissonanceWhy some combinations sound at rest and others sound tense and want to move.
InversionA chord with a note other than its root in the bass.
VoicingHow a chord's notes are spread out across the keyboard.
ArpeggioA chord played one note at a time instead of all together.
Chord ProgressionA sequence of chords moving through time, the backbone of a song.
TranspositionMoving music to a different key while keeping every interval the same.