'scale tone 7th chords'are the chords that result from 'harmomising' a scale.

For ex., C Maj.is made up of the notes C D E F G A B. Each of these 7 notes is a paticular ' scale degree'which is often indicated by a roman numeral.

For ex., the first scale degree ( in this case a C note ) would be 'I'; the fourth scale degree ( an F note in the key of C )would be 'IV'; the fifth scale degree ( a G note in the key of C )would be 'V'

We can take each note in the scale and 'harmonise'it. ie. change it from a simple note into a chord,by adding additional notes to it ( 3rd )from the scale.

For ex.,if we take the C note ( our I scale degree )and add the 3rd note above ( E ) and a 3rd above that ( G ) we wind up with the notes C,E&G - a C major chord.

What we have done is to harmonise the C note,resulting in a C Major chord.( Chord I in the key of C )

SCALE BREAK UP:

1. C (I)Major 1 3 5
2. D (ii)Minor 1 b3 5
3. E (iii)Minor 1 b3 5
4. F (IV)Major 1 3 5
5. G (V)Major 1 3 5
6. A (vi)Minor 1 b3 5
7. B (vii)Diminished 1 b3 b5

These are triads.( 3 note chords )We play these on our bass as arpeggios.

By adding the 7th we get the following:

1. C Maj 7 notes used 1 3 5 7 ( C E G B )
2. D min 7 " " 1 b3 5 b7 ( D F A C )
3. E min 7 " " 1 b3 5 b7
4. F Maj 7 " " 1 3 5 7
5. G Dom7 " " 1 3 5 b7
6. A min 7 " " 1 b3 5 b7
7. B dim 7 " " 1 b3 b5 b7,

We can do this any major scale.