August 01, 2011

More 7th Chords on C6th

Last year I posted about positions for 7th chords on C6th.  To recap, here are the handy positions for playing I, IV and V 7th chords in the key of E, using the the A to Bb lever, the C to C# lever, and P5 which lowers G to Gb.


A7   E7   B7     A7   E7   B7
1   __________________________________
2 E ___3____4____5______9____10___11__
3 C ___3#___4____5#_____9____10#__11__
4 A ___3#___4#___5#_____9#___10#__11#_
5 G ___3b___4____5b_____9____10b__11__
6 E ___3____4____5______9____10___11__
7 C ___3#___4____5#_____9____10#__11__
8 A ___3#___4#___5#_____9#___10#__11#_
9   __________________________________
10  __________________________________
Let's call the A to Bb lever "A", the C to C# lever "C", and the G to Gb pedal "G".  We can then use this shortcut notation:

A7 = 3 ACG
E7 = 4 A
B7 = 5 ACG

A7 = 9 A
E7 = 10 ACG
B7 = 11 A

Now here's the other half of the puzzle.  You may already know that the C lever (C to C#) makes an A7 chord on strings 2 through 8.  If you add the E to Eb pedal P6 into the mix, you can create another complete set of 7th chords.

Let's call the E to Eb pedal "E".  In our shortcut notation, the new scheme looks like this:

A7 = 0 C
E7 = 1 CAE
B7 = 2 C

A7 = 6 CAE
E7 = 7 C
B7 = 8 CAE

Pedal 6 doesn't lower string 2 (it raises it to F) so we do lose that string in those CAE positions.  Here's the tab:


A7   E7   B7     A7   E7   B7
1   __________________________________
2 E ___0_________3___________7________
3 C ___0#___1#___3#_____6#___7#___8#__  C lever (C to C#)
4 A ___0____1#___3______6#___7____8#__  A lever (A to Bb)
5 G ___0____1____3______6____7____8___
6 E ___0____1b___3______6b___7____8b__  E pedal (E to Eb, P6)
7 C ___0#___1#___3#_____6#___7#___8#__  C lever (C to C#)
8 A ___0____1#___3______6#___7____8#__  A lever (A to Bb)
9   __________________________________
10  __________________________________

 
So again we have this handy thing going on where the I7, IV7 and V7 chords are all clustered together on 3 frets.  Now here's the mindblower.  When you combine these two systems, you have one of the three seventh chords in the key of E at every fret on the neck!


A7 = 0 C
E7 = 1 CAE
B7 = 2 C
A7 = 3 ACG
E7 = 4 A
B7 = 5 ACG
A7 = 6 CAE
E7 = 7 C
B7 = 8 CAE
A7 = 9 A
E7 = 10 ACG
B7 = 11 A

Amazing, isn't it?