Riff 1. E7–A7–E7
This boogie pattern represents a set of changes that regularly occur over the first four bars of a 12-bar blues: I–IV–I.
What makes the blues so unique is how it blends both major and minor sounds. An example of this is the prevalence of dominant seventh chords in the blues. <.div>
If you remember, dominant seventh chords contain both a major 3rd and a minor 7th, and in a 12-bar blues, the I, IV, and V chords are typically all dominant in quality.
As you can see here, although the V chord is not present, the I chord and IV chord are both dominant, resulting in a I7–IV7–I7 (E7–A7–E7) progression.
A benefit of having both major and minor tonalities present is the abundance of scale options available for soloing, including major and minor pentatonic, blues, and Mixolydian, among many others.
Our scale of choice here is E minor pentatonic (E–G–A– B–D). After a standard open-position blues lick (measure 1), the A7 chord is greeted with the open A string and a climb back up the E minor pentatonic scale. In measure 3, the E7 harmony is emphasized via a couple of low E string attacks and a repetitive triplet figure.
In measure 4, the solo is brought to a conclusion via a hammer-on from the E7 chord’s b7th (D) to its root (E).
For this four-bar solo, we put a couple of scale’s to work, E major pentatonic and A blues.
The opening phrase is a country-influenced legato climb up the extended form of the E major pentatonic scale, starting in open position.
After an octave jump on beat 1, the phrase works stepwise down the A blues scale before reversing course on beat 4 to target the root of the E7 change, played here at fret 5 of string 2.
After sliding up and down string 2, the solo descends the E major pentatonic scale to its final destination—the E note at fret 2 of string 4.
Riff 2. B7–A7–E7
This rhythm figure is a fully-fretted variation of the previous boogie pattern. Harmonically, the B7–A7–E7 progression (V7–IV7–I7 in the key of E) represents the last four bars of a 12-bar blues.
Sometimes you’ll see a return to the V7 chord in bar 4 (bar 12 in a 12-bar blues), but here, we stay on the I7 chord for two bars.
For this blues “turnaround” progression, we’re going to use the E blues scale (E–G–A–Bb–B–D) exclusively.
The phrase commences with a trio of eighth-note-triplet double stops.
On beat 1 of measure 2, the phrase acknowledges the new A7 harmony with the tonic, A, which is followed by a legato lick that culminates with a whole-step bend to the root of the E7 chord (measure 3). After a two-beat phrase that incorporates both the perfect 5th (B) and the diminished 5th (Bb), the solo resolves to the E note at fret 14 of string 4.
This four-bar phrase commences with a melodic motif that is restated in measure 2. The first phrase is rooted in B minor pentatonic, while the second is derived from A minor pentatonic.
The quarter-step bends the appear on beats 1 and 3 of both measures are another example of the major/minor dichotomy of the blues, as the resultant notes lie halfway between the minor 3rd and major 3rd of their respective chords.
In measure 3, the solo begins a two-measure ascent of the ninth-position box pattern of the E major pentatonic scale, culminating in a hammer-on to the E7 chord’s tonic.