Teoria Musical

Chord symbols, and how to read one without memorising anything

The songbook's notation read by fields, root, quality, extension, alteration and bass, each one answering a question.

iniciante · prático · formal · 3 conceitos

C7M(9)/E frightens whoever sees it for the first time, and it should not. A chord symbol is not a code to memorise: it is a sequence of fields, each one answering a specific question, always in the same order.

The five fields

Read from left to right:

  1. Root — which note names the chord
  2. Quality — major, minor, diminished, augmented
  3. Extension — how far the stack of thirds goes
  4. Alterations — what departs from the expected, in parentheses
  5. Bass — after the slash, when it is not the root

Not every symbol uses all of them. uses only the first.

Root

An upper-case letter, with an accidental if needed. C, D, E, F, G, A, B.

and are the same idea with an accidental.

Quality

With nothing after the letter, the chord is major: .

A lower-case m makes the third minor: .

dim or ° lowers the fifth as well: .

aug or + raises the fifth: .

Extension

A number says how far to stack thirds. 7 adds the seventh, 9 the ninth, and so on; each number includes the ones before it.

And here is the distinction most people trip on:

  • — minor seventh. The dominant chord, which asks for resolution.
  • — major seventh. A chord at rest, with no tension.

A 7 on its own never means a major seventh. For the major you have to say so: maj7, 7M or Δ, depending on the songbook.

Alterations

What departs from the expected goes in parentheses, with a sign:

  • — the ninth lowered
  • — the eleventh raised
  • — the fifth lowered

Brazilian songbooks usually write the same alterations in parentheses: C7(b9), C7(#11), C7(b5). They are the same symbol, and this site reads both spellings, but always prints the form without parentheses, so that the same symbol looks the same on every page.

And two cases that replace the third instead of adding a note:

  • — the fourth takes the place of the third
  • — the second takes the place of the third

A sus chord is neither major nor minor: without a third, it lacks the degree that decides. That is why it sounds suspended, and why it almost always resolves onto the third right after.

Bass

After the slash goes the bass note. is a C chord with E underneath: the same notes, another weight.

The bass need not even belong to the chord: is legitimate and common, and sounds like a D chord with a lot on top.

Reading the symbol from the start

C7M(9)/E, field by field:

  • C — root C
  • 7M — major seventh
  • (9) — plus the ninth
  • /E — E in the bass

C, E, G, B, D, with E underneath. Nothing to memorise: each symbol was read in its place. Printed in this site's convention, the same chord is .

How it actually shows up

The II–V–I, the most common sequence in popular music. Three symbols, and each is read by the same procedure.

What to take from this

A chord symbol is positional notation. Root, quality, extension, alteration, bass, always in that order. Whoever reads by fields can decipher a symbol they have never seen; whoever memorised formats gets stuck at the first one outside the familiar repertoire.