The Chords of the major scale
Butlers Jazz Workshop
There are 12 major scales in (Western) music each one starting on a separate note
C Db D Eb E F Gb G Ab A Bb B (see note below)
Each note above has a major scale starting on that note.
Chords can be built up on each note of the scale by playing evry other note in the scale (Musically called Thirds) like this
Chord 1 C E G
Chord 2 D F A
Chord 3 E G B
Chord 4 F A C etc
Carry on in C to get all seven chords
The same thing can be done in any of the other 12 major scales ie
Chord 1 F A C
Chord 2 G Bb D
Chord 3 A C E etc.
In jazz, we extend this to four note chords (and beyond!)
So in C
Chord 1 C E G B
Chord 2 D F A C
Chord 3 E G B D etc
In every major scale therefore you can have 7 four note chords
They all have names
Chord 1 Major 7th
Chord 2 minor 7th
Chord 3 minor 7th
Chord 4 Major 7th
Chord 5 Dominant 7th (or just 7th for short)
Chord 6 minor 7th
Chord 7 minor seventh flat 5 (or half dimished for short)
Don't worry too much about the names, until you want to read a chart (the jazz man's term for sheet music or chord sheet) then it becomes very useful.
In C therefore chord 1 is C Major 7th
chord 5 is G dominant 7th (or G7th for short)
By using just the 12 major scales, a musician can build up a whole library of chords for use in playing and improvising.
There are of course many more chords (and scales) available to the jazz musician, but more about that another time!