Open any chord page and you’ll see the same chord described four different ways: as notes, as intervals, as a formula, and as scale degrees. They aren’t four different chords — they’re four lenses on the same one. Once you can switch between them, every chord in the catalogue gets simpler.
Anatomy Explorer
Pick a root and a quality. The same chord appears as notes, intervals, formula, and scale degrees — all updating together.
Root note
Chord quality
Now showing
F♯ — Major
1. Notes
F♯–A♯–C♯
The actual letter names you press.
2. Intervals
P1–M3–P5
Distance from the root, measured in scale steps.
3. Formula
1–3–5
The recipe — relative to the major scale of the root.
4. Scale Degrees
1–3–5
Position within the parent scale (1st, 3rd, 5th degree…).
The most concrete description of a chord is the list of notes it contains. F♯ Major is F♯ – A♯ – C♯. Three notes, three keys you press, done. No Roman numerals, no math, just letter names.
What feels arbitrary at first — why F♯ and A♯ and not G♭ and B♭? — is actually a deliberate spelling choice. A chord uses every other letter (F, A, C — skipping G and B), so each note gets a unique letter name. Spelling it as G♭–A♯–C♯ would put two notes on the same staff line and make the chord unreadable. The sharps and flats follow from the chord’s position in its parent key.
When notes are most useful: when you’re sight-reading, looking up a fingering, or playing a chord you’ve never seen before. Notes tell you exactly which keys to press, right now.
Same root, different qualities
All seven chords below share the root C. The 3rd, 5th, and (sometimes) 7th change to make each quality.
C = C–E–G
An interval is the distance between two notes. Every chord is built from a stack of intervals measured up from the root.
A major triad stacks a Major 3rd on top of the root, then a Perfect 5th. Its full interval list is P1 – M3 – P5. A minor triad swaps the Major 3rd for a Minor 3rd, giving P1 – m3 – P5. That single half-step difference is the entire reason a minor chord sounds sad and a major chord sounds bright.
Intervals come in five quality categories: Perfect (P — 4ths, 5ths, octaves), Major (M — 2nds, 3rds, 6ths, 7ths), Minor (m — one half-step smaller than Major), Diminished (d — one half-step smaller than Perfect or Minor), and Augmented (A — one half-step larger than Perfect or Major).
When intervals are most useful: when you’re analyzing why a chord sounds the way it does, or when you’re transposing a chord to another key. Intervals are key-independent — a Major 3rd is a Major 3rd whether the root is C or F♯.
Interval ladder
Click a note to measure its interval from C. The interval names tell you both the type and the size.
The formula is the most compact way to describe a chord. It uses scale-degree numbers from the major scale of the root, with sharps and flats showing where notes have been raised or lowered.
Major triad: 1–3–5. Take the 1st, 3rd, and 5th notes of the major scale of your chosen root. For C major, that’s C–E–G. For F♯ major, F♯–A♯–C♯. Same recipe, different ingredients.
Minor triad: 1–♭3–5. Take the 1st, 3rd, and 5th of the major scale, but lower the 3rd by a half-step. C major’s 3rd is E; lower that to E♭ and you get C minor.
Why it’s built on the major scale: by historical convention. The major scale is the universal reference grid for chord formulas. A formula like 1–3–5–♭7 (dominant 7th) means “take 1, 3, 5 from the major scale, and use a flat 7th instead of the natural 7th.” Once you memorize the major scale of every key, every chord formula resolves instantly.
| Chord | Symbol | Formula | Intervals | In C |
|---|---|---|---|---|
| Major | C | 1–3–5 | P1–M3–P5 | C – E – G |
| Minor | Cm | 1–♭3–5 | P1–m3–P5 | C – E♭ – G |
| Diminished | C° | 1–♭3–♭5 | P1–m3–d5 | C – E♭ – F♯ |
| Augmented | C+ | 1–3–♯5 | P1–M3–A5 | C – E – A♭ |
| Major 7th | Cmaj7 | 1–3–5–7 | P1–M3–P5–M7 | C – E – G – B |
| Dominant 7th | C7 | 1–3–5–♭7 | P1–M3–P5–m7 | C – E – G – B♭ |
| Minor 7th | Cm7 | 1–♭3–5–♭7 | P1–m3–P5–m7 | C – E♭ – G – B♭ |
When the formula is most useful: when you’re learning a new chord type, transposing on the fly, or comparing two chords side-by-side. The formula reveals the family resemblance — major and minor differ by one symbol; dominant 7th and major 7th differ by one symbol.
Scale degrees describe a chord’s position within a parent key. They answer the question: “If we’re in C major, what is this chord doing?”
Every major scale produces seven natural triads — one starting on each scale degree. In C major: C is the I chord, D minor is ii, E minor is iii, F is IV, G is V, A minor is vi, and B diminished is vii°. Roman numerals show the degree (capital = major-quality, lowercase = minor-quality).
Formula vs scale degrees — the subtle difference: the formula describes a chord on its own (always relative to the major scale of that chord’s root). Scale degrees describe a chord’s role inside a key. F major’s formula is always 1–3–5. But in C major, F is the IV chord; in F major itself, it’s the I chord. Same notes, different role.
Diatonic chords in C major
Each scale degree of the C major scale produces a chord built from notes of that scale. Click a Roman numeral to see which degrees light up.
I chord — C – E – G (degrees 1, 3, 5 of C major) — Major
Every chord page on this site shows the same four pieces of information stacked in the header. Here’s what each line is telling you:
F♯ Major
None of these is more correct than another — they’re different tools. Notes are best for sight-reading. Intervals are best for analysis. Formulas are best for memorizing chord types. Scale degrees are best for understanding harmony in context. Fluent musicians switch between them constantly without thinking about it.
A major 3rd is 4 half-steps; a minor 3rd is 3. The same letter-name interval (third) comes in two sizes. Major 3rd = bright, open. Minor 3rd = darker, narrower. Whether a triad is major or minor is decided by which 3rd sits between the root and the middle note.
Yes — by convention, chord formulas use the major scale of the root as the reference grid. Even when describing a minor chord, the formula 1–♭3–5 is read against the major scale (lower the 3rd by a half-step). This way every chord type has one canonical formula regardless of which key you’re in.
They describe the same thing in two notations. The formula 1–3–5 maps to the intervals P1–M3–P5; 1–♭3–5 maps to P1–m3–P5. Formulas are compact and great for quick lookup; interval names are explicit and great for analysis.
Two reasons. First, Roman numerals signal that the number refers to a chord, not a single note (so “ii” means “the chord built on the 2nd scale degree,” not just “the second note”). Second, the case shows the chord quality at a glance — capital for major-quality (I, IV, V), lowercase for minor-quality (ii, iii, vi), and a degree symbol for diminished (vii°).
Not all at once. Most beginners start with notes (which keys to press), then learn formulas (so they can build any chord on any root), then pick up intervals and scale degrees as they get into harmony and song analysis. Each layer adds depth, but you can play music well at every stage.
Fingering is a fifth, more practical layer that sits on top of the four described here. Once you know the notes, fingering tells your hand which finger plays which note. For a triad in root position the standard right-hand fingering is 1–3–5 (thumb, middle, pinky); the standard left-hand is 5–3–1 (pinky, middle, thumb).
Chord Mastery Series