Chords

A chord is a root followed by an optional descriptor that says what's built on top of it:

C        F#m7       Bbmaj9       G7b9       Dm7b5/F
└root    │ │        │   │        │  │       │    └ bass
         │ └family  │   └ext     │  └alt    └ everything else
         └quality   └root        └family

A bar of varied chord qualities, engraved:

This page is about writing one chord, on its own. (How chords carry their quality forward from bar to bar — "chord memory" — comes later.) Everything after the root reads left to right: quality → seventh family → extensions → alterations → additions/omissions → slash bass.

The root

The root can be written three ways, and they're interchangeable — pick whatever fits the chart:

Numbers and numerals are relative to the key set in the header (see Structure) — 1 in #C is C, 1 in #G is G. That's what makes a Nashville or Roman chart transposable.

The same descriptor works on any root, so every chord below could equally be written Cmaj7, 1maj7, or Imaj7.

Quality — the triad

Quality is the basic three-note shape. Major is the default — a bare root is a major triad.

Quality on numbers and numerals

For Roman numerals, case carries the quality — uppercase is major, lowercase is minor:

I  ii  iii  IV  V  vi  vii      → I, iim, iiim, IV, V, vim, viim

For Nashville numbers, a bare number is major; add m for minor:

1  2  6        → major
1m  2m  6m     → minor

The seventh — chord family

Adding a seventh puts the chord in a family. A chord with no seventh is just a triad.

Extensions — 9th, 11th, 13th

Extensions stack thirds above the seventh. Writing 9, 11, or 13 on a plain root implies a dominant 7th underneath (so C9 is C7 + a 9th); combine with maj/m to keep a major- or minor-7th underneath.

Alterations

Alterations sharpen or flatten a single tone — most often the 5th, 9th, 11th, or 13th. Write the accidental (b/#) directly before the degree:

Additions and omissions

• Add a tone without implying the notes below it: add — Cadd9 is a major triad plus a 9th, with no 7th.
• Remove a tone: no — C7no3 drops the 3rd, Cno5 drops the 5th.

Slash bass

Put a bass note other than the root after a /:

C/E        major triad over E
Dm7/G      Dm7 over G
F/A        F over A

The bass takes the same systems as the root, so 1/3 (Nashville, the 1 chord over the 3rd degree) means the same thing as C/E in C.

One exception: V/V in Roman numerals

There's a single twist. Between two Roman numerals, / doesn't mean slash bass — it's a secondary (applied) chord, the way analysts write them:

V/V        "five of five" — the dominant of the dominant
V/vi       the dominant of the vi chord
V7/V       …with a seventh

V/V reads as "the V chord in the key of V." In C, the second V is G, so V/V is the dominant of G — a D chord (V7/V is D7). It's a chromatic chord that pulls toward the V, not a G over a G bass.

This only applies to Roman / Roman. A Roman numeral over a note or a number — I/3, V/B — is still an ordinary slash bass, as are all letter-name (C/E) and number (1/3) slashes.

Figured bass and inversions

A ^ after a chord adds a figured-bass figure — the stacked numbers analysts use for inversions. On a Roman numeral these are real inversions: the chord actually gets the right bass note, so it resolves and transposes correctly, while the chart still shows the figure.

V^6    V^64    V^65    V^43    V^42

So in C, V^65 is shown as V^65 but is really a G7 with B in the bass — and it follows the chord's actual notes, so III^65 (a chromatic chord) puts the right G♯ in the bass, not a plain G. Any numeral takes a figure — ii^65, IV^64, vii°^6. Because the figure sits behind the ^, the chord symbol stays clean — a plain V6 (no ^) is still an ordinary sixth chord. A duration goes after the figure as usual (V^65_4).

A figure with a dash is a suspension rather than an inversion — V^4-3 marks a 4–3 suspension.

Text annotations use quotes

The ^ figures are structural (they change the chord). For a plain text annotation — a cue, a reminder — use quotes:

G^"watch the push"     text above the chord
G_"quietly"            text below (subscript)
Cmaj7"as written"      text attached to the chord

So ^65 is an inversion, but ^"65" (quoted) would just be the text "65" floating above.

Putting it together

The pieces stack in order — root, quality, family, extensions, alterations, bass:

Am7         A  + minor + 7th
Cmaj9       C  + major 7th + 9th
G7b9        G  + dominant 7th + flat 9th
F#m7b5      F# + half-diminished 7th
Bbmaj7/D    Bb + major 7th, over D

What's next

• Notation Systems — the three interchangeable ways to write the root (letter names, Nashville numbers, Roman numerals), how they relate to the key, and how flats and the ambiguous b7 are resolved.