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.
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:
- Root — which note names the chord
- Quality — major, minor, diminished, augmented
- Extension — how far the stack of thirds goes
- Alterations — what departs from the expected, in parentheses
- 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.