Use these free music theory calculators to answer a musical question, hear the result, and keep writing.
Each tool focuses on a specific task: finding chords in a key, spelling a chord, identifying harmonic function, building a progression, calculating a secondary dominant, improving voice leading, comparing scales, or planning a key change. There is no account to create, and the main results are playable in the browser.
Choose A Music Theory Tool By Question
| If you want to know… | Start here | What you get |
|---|---|---|
| Which chords belong to this key? | Chords in a Key Calculator | Diatonic triads, sevenths, extensions, and borrowed chords |
| What notes are in this chord? | Chord Piano Calculator | Exact chord tones and a keyboard view |
| What progression can I try? | Chord Progression Generator | Playable progressions by key, genre, and mood |
| What job does each chord perform? | Functional Harmony Calculator | Tonic, predominant, and dominant analysis |
| What dominant resolves to this chord? | Secondary Dominant Calculator | The applied dominant and its resolution |
| How can these chords move smoothly? | Voice Leading Calculator | Optimized keyboard or SATB voicings |
| Which notes define this scale? | Scale Formula Calculator | Notes, degrees, step pattern, and playback |
| How can I change keys? | Key Modulation Calculator | Shared chords and playable transition routes |
Chord And Key Calculators
The Chords in a Key Calculator is the best starting point when you know the key but not the available harmony. Select a tonic and major or minor mode to see the chord built on every scale degree. Switch between triads, seventh chords, and extensions, then compare borrowed chords when the diatonic set feels too predictable.
Use the Chord Piano Calculator for the opposite problem: you already have a chord symbol and need its notes. It spells the chord by harmonic function and shows the exact tones on a keyboard, including seventh chords, extensions, suspended chords, and altered dominants.
The Interactive Circle of Fifths connects those two views. It shows key signatures, neighboring keys, relative major and minor relationships, and the diatonic chords inside the selected key.
Chord Progression And Harmony Tools
The Chord Progression Generator creates a practical starting point by key, genre, and mood. It includes full-progression playback, Roman numerals, bass-motion guidance, shareable settings, and a direct route into the voice-leading tool.
When you already have a progression, use the Functional Harmony Calculator to see how its chords behave. Tonic chords create stability, predominant chords prepare motion, and dominant chords create pressure toward resolution. Hearing those roles in sequence is usually more useful than memorizing labels alone.
The Secondary Dominant Calculator answers a narrower question: which dominant seventh chord temporarily points toward a chosen diatonic chord? It shows the applied dominant, target, chord tones, and resolution so you can hear why the chromatic chord still sounds directed.
Voice Leading And Arrangement Calculators
Chord symbols describe harmony, but they do not specify where each note should move. The Voice Leading Calculator compares possible voicings and reduces unnecessary motion between chords. You can audition the original symbols against the optimized note arrangement and choose keyboard or SATB-style spacing.
For the low end, the Chord Progression Generator includes a bass-motion profile that compares the root path and movement shape of each result. A progression can feel completely different when the bass line changes even if the chord symbols remain the same.
Scale And Modulation Calculators
The Scale Formula Calculator shows the notes, scale degrees, and whole-step or half-step pattern for major, minor, modal, pentatonic, blues, and other scales. Use its playback to connect the formula with the scale’s actual color.
The Key Modulation Calculator compares a source and destination key, finds shared chords, and suggests routes between them. It is useful when a chorus, bridge, or final section needs a lift but an immediate key change sounds too abrupt.
A Practical Music Theory Workflow
- Find the available harmony with the Chords in a Key Calculator.
- Generate or enter a progression and listen to the complete loop.
- Check each chord’s function with the Functional Harmony Calculator.
- Add directed chromatic color with the Secondary Dominant Calculator.
- Refine the result with the Voice Leading Calculator.
- Test a contrasting key with the Key Modulation Calculator.
The calculators are most useful when they shorten the distance between a theory idea and an audible decision. Treat each result as material to test, edit, and play—not as a rule that has to be followed.
Pair Theory With Ear Training
Music theory becomes more practical when you can recognize the same relationships by sound. The ear training exercise directory includes focused drills for intervals, chords, scales, notes, tuning, EQ frequencies, and synthesizer filters.
Start with one calculator, listen to its result, and then find the same relationship on your instrument or in a piece of music. That small loop turns reference information into usable musical vocabulary.