Interactive Tool
Chord & Scale Builder
Learn harmony visually and by ear.
C Major
C Major
The cornerstone of Western music. Three notes stacked in a bright, stable arrangement that feels complete and resolved.
Intervals
Emotional Vibe
Bright & triumphant
Songs You Know
Learn the Fundamentals
Piano Chords 101
Everything you need to understand how chords work — the theory, the math, and the emotion behind every sound.
🎵 What is a Chord?
A chord is two or more notes played together. The most basic chords are triads — three notes built by stacking thirds. C major = C–E–G: a major third (4 semitones) above C, then a minor third (3 semitones) above E.
Inversions
Inversions don't change what the chord is — just which note sits on the bottom. They make chord progressions sound smoother.
⚖️ Major vs Minor
☀️ Major
Root + Major 3rd (+4) + Perfect 5th (+7)
Bright · Happy · Stable
🌧️ Minor
Root + Minor 3rd (+3) + Perfect 5th (+7)
Dark · Sad · Moody
Just one semitone — lowering the middle note by a single step — shifts the entire emotional color from bright to somber. That's the power of the third.
Semitone Formula
🎷 Seventh Chords
Add one more third on top of a triad and you get a seventh chord — four notes with richer color. These are the building blocks of jazz, blues, and cinematic harmony.
| Type | Symbol | Intervals | Feel | Genre |
|---|---|---|---|---|
| Major 7th | Cmaj7 | 1 – 3 – 5 – 7 | Dreamy, romantic | Jazz, Pop |
| Dominant 7th | C7 | 1 – 3 – 5 – ♭7 | Tense, bluesy | Blues, Rock |
| Minor 7th | Cm7 | 1 – ♭3 – 5 – ♭7 | Smooth, soulful | Jazz, R&B |
| Half-Diminished | Cø7 | 1 – ♭3 – ♭5 – ♭7 | Tense, unresolved | Jazz |
| Diminished 7th | C°7 | 1 – ♭3 – ♭5 – 𝄫7 | Very tense, dramatic | Classical, Film |
📐 The Math Behind Chords
Intervals correspond to frequency ratios. Simple whole-number ratios sound consonant — that's why major chords feel so stable.
Pure (Just) Intonation Ratios
A pure C major triad has frequencies in ratio 4 : 5 : 6. Modern pianos use equal temperament — each of 12 semitones has ratio 2^(1/12) ≈ 1.059 — slightly detuning thirds so every key sounds the same.
🎭 Creating Mood with Progressions
It's not just individual chords — sequences of chords (progressions) shape a song's entire emotional story.
💡 Tips for Beginners
Learn triads first
Master major and minor shapes in all 12 keys. Block them and arpeggiate them to build muscle memory.
Use a chord chart
A simple chart (C = C–E–G, Cm = C–E♭–G) gives you a visual map to come back to.
Practice inversions
Playing E–G–C instead of C–E–G makes transitions smoother. Same chord, different feel.
Start with I–IV–V–vi
These four chords cover hundreds of songs. In C major: C, F, G, Am.
Experiment with 7ths
Turn Cmaj into Cmaj7 or C7 and hear how one extra note changes the entire color.
Apply to real songs
Find chord sheets for songs you love. Real music is the best and most satisfying practice.