7th Chords

7th Chords found in the Major Scale

Just as the Major Scale contains sevenn triads (3 note chords), it also contains seven 7th chords. In order to see what they are, let's take another look at the C Major Scale...

The first chord in C, is obviously C Major 7th, it's made up of the notes C, E, G and B. Following this pattern the next chord that we find in the scale of C Major is D, F, A and C which is the chord of D Minor 7th. Then we have E, G, B and Dwhich gives us E Minor 7th. Next up is F, A, C and E which is F Major 7th. Then G, B, D and F or G Dominant 7th. Then A, C, E and G which is A Minor 7th. The last chord is B, D, F and A which contains both a flat 3rd, a flat 5th and a flat 7th which gives us a Half-Diminished Chord, in this case B Half-Diminished.

Here's how each chord looks on the Fretboard...

C Major 7th or CΔ7 (C, E, G, B)
G Dominant 7th or G7 (G, B, D, F)
D Minor 7th or Dm7 (D, F, A, C)
A Minor 7th or Am7 (A, C, E, G)
E Minor 7th or Em7 (E, G, B, D)
B Half-Diminished or Bø (B, D, F, A)
F Major 7th or FΔ7 (F, A, C, E)
 

But what about the other Keys/Scales?

The other scales/keys also contain seven 7th chords, they always follow the order: Major 7th (Δ7), Minor 7th (m7), m7, 7, Δ7, m7 and Half-Diminished (ø).

For easy reference, here's a chart of all the keys and associated chords...

KEY I II III IV V VI VII
C# C#Δ7 D#m7 E#m7 F#Δ7 G#7 A#m7 B#ø
F# F#Δ7 G#m7 A#m7 BΔ7 C#7 D#m7 E#ø
B B7Δ7 C#m7 D#m7 EΔ7 F#7 G#m7 A#ø
E EΔ7 F#m7 G#m7 AΔ7 B7 C#m7 D#ø
A AΔ7 Bm7 C#m7 DΔ7 E7 F#m7 G#ø
D DΔ7 Em7 F#m7 GΔ7 A7 Bm7 C#ø
G GΔ7 Am7 Bm7 CΔ7 D7 Em7 F#ø
C CΔ7 Dm7 Em7 FΔ7 G7 Am7
F FΔ7 Gm7 Am7 BbΔ7 C7 Dm7
Bb BbΔ7 Cm7 Dm7 EbΔ7 F7 Gm7
Eb EbΔ7 Fm7 Gm7 AbΔ7 Bb7 Cm7
Ab AbΔ7 Bbm7 Cm7 DbΔ7 Eb7 Fm7
Db DbΔ7 Ebm7 Fm7 GbΔ7 Ab7 Bbm7
Gb GbΔ7 Abm7 Bbm7 CbΔ7 Db7 Ebm7
Cb CbΔ7 Dbm7 Ebm7 FbΔ7 Gb7 Abm7 Bbø