UD#45 What do the Sevens Mean? (The Numbers in Chord Names)

Posted on October 13, 2014 by guido

UD#45: What do the SEVENS mean? (The Numbers in Chord Names)
from Ukulele in the Dark
w/ Guido Heistek

EVER WONDER what the numbers in chord names mean? C7, F6, A7…

A student asked me an interesting question in class the other day:

“What makes jazz different from other types of music?”

This is a very tough question to answer but one potential answer did pop into mind:

“Jazz music tends to use 7th chords (ex. Cm7, C7, Fmaj7) as opposed to triads or three note chords (ex.  Cm, F, Bbm).”

What’s a seventh chord?

A seventh chord is a kind of four note chord.

As we learned in https://ukuleleinthedark.com/ud-13-ukulele-music-theory-abacus-ii
chords are built from scales.

If we take the 1st, 3rd and 5th note in a major scale we get a major chord. In the key of C this gives us C, E and G (the three notes in a C major chord). We call this kind of chord a triad because it has three notes. To play the three notes of this chord across the four strings of the ukulele we have to double one of the notes:

Try this!

ABOVE: The notes of a C major chord one at a time, followed by the three notes of the C major chord arranged across the four strings. Notice the C note is doubled in the strummed version across four strings.

BONUS INFO: The “recipe” (thank you Andrew Smith) for making a major chord can be written simply like this: 1, 3, 5.

Let’s make a seventh chord!

If we take the 1st, 3rd, 5th and 7th notes in a major scale we get a major 7th chord (ex. Cmaj7).  In the key of C this gives us four notes: C, E, G and B (1st, 3rd, 5th and 7th notes in the C major scale). We call it a seventh chord because we have added the 7th note in the scale (B), which is also the note that makes the chord a 4-note chord, and also gives the chord it’s distinctive sound. Let’s make a Cmaj7 chord:

Try this!

ABOVE: The four notes of the Cmaj7 chord, followed by the four notes in the chord arranged across the 4 strings.

BONUS INFO:
-The recipe for making a major 7th chord can be written like this:
1, 3, 5, 7.
-Major 7th chords can be notated a few different ways: Cmaj7, C∆, and CM7 are the most common.

“How is a Cmaj7 different from a C7 chord? Aren’t they the same?”

No, a C7 is a little different from a Cmaj7.

To make a Cmaj7 chord we use the 1st, 3rd, 5th and 7th notes in the major scale.

When we make a C7 chord we use the 1st, 3rd, 5th, 7th notes in the C major scale but we flatten the 7th note. This gives us four notes: C, E, G, and Bb.

Try this!

ABOVE: C7 one note at a time, followed by across all four strings.

BONUS INFO:
-C7 means the same as C dominant 7th. You may have heard that term before.
-The recipe for a dominant 7th chord can be written: 1, 3, 5, b7

“What about minor 7th chords?”

To create a C minor 7th chord we use the 1st, 3rd, 5th and 7th notes in the C major scale but we flatten the 3rd note, and the 7th note in the chord. This gives us these four notes: C, Eb, G and Bb.  Here’s a C minor 7 (Cm7)

ABOVE: Cm7 one note at a time, followed by across all four strings.

BONUS INFO:
-There are few different ways of notating a C minor 7th chord: Cm7, Cmin7, C-7 are the most common.
-The recipe for a minor 7th chord can be written like this: 1, b3, 5, b7.

“FLAT 5?”

To make a minor 7th flat 5 chord (ex. Cm7b5) we use the 1st, 3rd, 5th and 7th notes in the C major scale but we flatten the 3rd, 7th AND 5th note in the scale. This gives us these four notes: C, Eb, Gb, Bb.

Try this!

ABOVE: Cm7b5 one note at a time, followed by across all four strings.

BONUS INFO:
-A “minor 7th flat 5” chord can also be called a “half diminished” chord.
-Here are the most common notations: Cm7b5, Cø, C-7b5.
-The recipe for a minor 7th flat 5 chord: 1, b3, b5, b7.

If you are interested in more study along these lines please take a look at these links on Chord Spelling:

http://trainer.thetamusic.com/en/content/spelling-chords

http://quizlet.com/8911541/7th-chord-spelling-flash-cards/

Okay, hope you’ve enjoyed this week’s newsletter! All the best,

Guido

p.s. Here are all the recipes again. Plus a few more:

Major (ex.C): 1, 3, 5
Minor (ex. Cmin): 1, b3, 5
Major Seventh (ex. Cmaj7): 1, 3, 5, 7
Dominant Seventh (ex. C7): 1, 3, 5, b7
Minor Seventh (ex. Cmin7): 1, b3, 5, b7
Minor Seventh Flat Five (ex. Cmin7b5): 1, b3, b5, b7

Diminished Seventh (ex. Cdim): 1, b3, b5, bb7(6)
(note: For a diminished 7th chord we flatten the 7th note twice which effectively makes it the 6th note)

Sixth (ex. C6): 1, 3, 5, 6
Minor 6th (ex.Cmin6): 1, b3, 5, 6

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