This example uses sets of third intervals, both major and minor.
They are derived from the mixolydian scale.
Move the pattern in bars 1 and 2 up to the IV and V position to get the riff for the C7 and D7 groove.
All these riffs are played relative to the tonic.
Find the tonic first and then play the riff. The tonic for this riff (a G) is the last note you play.
The audio for this example is split in the pattern on the middle strings (G) and the pattern on the high strings (C).
Move the C pattern two frets up to get the D7 chord variation.
Note: You’ll find Examples 1-4 in the Swing- and Jump-Blues Guitar book.
Example 5 is how you can use them in a complete Blues Progression.
Thirds are all over the neck. You can form a third interval on any two adjacent strings, like in this example.
Move the G riff up 5 frets to get the C7 variation and another 2 frets to get the D7 pattern.
Another groovy one that is similar to Hollywood Fats’ riff in “She’s Dynamite”.
Note: Inner Logic
As with tritone intervals, there is an inner logic to playing third intervals over these chords.
First listen to this example. What’s goin’ on?
Whenever you use a riff with notes from the mixolydian scale and you change chords (for instance from G7 to C7), you’ve got to change scales.
The first pattern on G7 uses notes from G mixolydian. On C7 you use notes from C mixolydian.
These scales look a lot alike (see Scales / Chords). By changing only one note of the first G7 riff, you can use it on a C7 chord. Move this one up two frets and you’re set for D7.
Whenever you play a riff with intervals or broken chords, there is a good chance you can play the same riff on the IV and V chord.
If it contains the third of the I chord (B in G7), move that note down one fret. Bingo! Move the riff up two frets from there to get the V chord version.
If the riff contains the seventh of the I chord (F in G7), you’ve also got to change the riff when you land on the V chord. Look at bar 9 of example 5. On beat two you’re playing an F# on the B string, not an F!
On the C7 the F sounds hunky dory because it’s part of the C mixolydian scale. These kinds of riffs are used a lot by experienced players.
Instead of moving all over the neck to play these riffs, they change one note and look way cool while giving the girls (or boys …) in the first row the eye.