My last 2 posts explained the concept of “key shapes”, an
alternate way to find the chords in any key by following
the shape and sequence the chords formed on the fret-
board. Those 2 posts referred to major keys, the next 2
posts will refer to blues keys. Blues harmony is the basis
of most modern music; jazz, rock, modern country, R&B,
etc. so even if you don’t like blues music you still need to
understand the harmony! As with the previous 2 posts on
key shapes, the theory behind blues harmony is advanced.
MY book “Take Control: for guitar”, explains this in more
detail, but the short answer is blues harmony equals a
major plus a minor key added together. This major/minor
combo gives it both a distinct sound and a distinct shape.
Blues keys jump 3 frets from the root, then 2 frets while
major keys jump in 2 plus 2 fret intervals. Below I list the
chords in the key of E blues followed by the physical
shape in a table. Just follow the fret number on the left,
notice any degree name to the right and play the chord
listed in the type 1 (6th string root), or type 2 (5th string
root) columns.
KEY OF E BLUES: E,G,A,B,C,D (all major chords, although
E,A, and B can be minor as well).
fret# degree type1 chord degree type2 chord
0 I E major * IV A major
1
2 V B major
3 bIII G major bVI C major
4
5 *IV A major bVII D major
(* I have repeated the same IV/A major chord in 2 different
locations to emphasize the 3/2 fret spacing)
Notice the root chord of the key, E major, is a type I chord
open. The root chord for this pattern will always be a type
I chord. The next chords go up 3 frets to G major and 2 more
frets to A major on fret 5. This plus 3fret/2 fret motion is
repeated in the type 2 column with C major and D major and
is what I use to identify blues keys. The only chord outside
this 3/2 fret pattern is the V chord (B), which is 2 frets above
the root chord. This illustrates an important point, the I,IV,
and V chords are in the same location for both major and
blues keys! (Check the previous 2 posts if needed.) This
means that if your song only contains I,IV, and V chords,
your key could be either major or blues! In the final post
I will discuss how to solve this problem, as well as show 2
different blues keys to further illustrate the key shape.
