Players
Duane Allman
Duane Allman is the standard by which all rock slide guitar is measured. In three years of recording before his death at 24, he defined what slide guitar could be in a rock context - melodic, vocal, harmonically aware, and completely original. But his fretted playing was equally deep. Understanding Duane means understanding how blues, gospel, and country vocabulary fused into something that had never existed before.
Start with E Mixolydian
Open E tuning puts the root on every open string. Mixolydian fits naturally over the dominant 7th chords that define the Allman Brothers sound.
Open E tuning and the slide vocabulary
Duane played slide in open E tuning — strings tuned to E, B, E, G#, B, E from low to high. This means every open string is a chord tone of E major, and laying the slide across any fret produces a full major chord. The harmonic implications are immediate: every position on the neck has a built-in chord relationship, not just a scale position.
His slide phrases were not scale runs. They were melodic statements that moved between chord tones with the slide as a voice-leading device. Where most slide players move the slide in one direction and stop, Duane curved his phrases — approaching a target note from below, landing on it, vibratoing it, then releasing back down in a way that mimicked a vocalist's natural phrasing.
Open E tuning: every string a chord tone
Root, 3rd, and 5th on every string. The slide becomes a harmonic device, not just a pitch-shifting tool.
Mixolydian: the dominant blues voice
The Allman Brothers sound is built on dominant 7th harmony — I7, IV7, V7 chords where the flat 7th is always present. Mixolydian, the major scale with a flat 7th, sits perfectly over this harmony. Duane used it not as a modal exercise but as his natural melodic language over dominant grooves. The scale's major 3rd gave his lines a brightness that straight minor pentatonic could not approach, while the flat 7th kept everything rooted in the blues.
His Mixolydian phrasing had a gospel quality — wide intervals, strong melodic shapes, phrases that landed on the 3rd or the root rather than running through the scale chromatically. Gospel music uses the same dominant 7th harmony and the same major-over-dominant approach. Duane absorbed it directly from the Southern gospel and R&B he grew up listening to.
Blues scale: the emotional anchor
Beneath the Mixolydian sophistication, Duane's vocabulary was grounded in the pentatonic and blues scale. The flat 5 in the blues scale appears at specific moments - never as a passing tone rushed through, always as a held emotional statement. On slide, he could bend the flat 5 continuously upward toward the 5th or downward toward the 4th, turning a single note into a complete phrase.
His blues scale playing had a directness borrowed from the three Kings - BB, Albert, and Freddie. He understood that the minor 3rd over a major chord creates tension that only the major 3rd can fully resolve, and he used that tension deliberately: establishing the minor blues feel, then resolving to the major 3rd for a moment of brightness before returning to the tension.
E major pentatonic: the gospel thread
Major pentatonic over dominant chords gives the bright, resolved quality that separates Duane's sound from minor-only blues players.
Harmony guitar: two voices as one
Duane's work with Dickey Betts on harmony guitar parts is some of the most influential dual-guitar writing in rock. The harmony lines are diatonic thirds and sixths - intervals where both notes belong to the same scale, so the two-voice phrase sounds like a single melodic statement rather than two guitars playing different things.
In practice: one guitar plays the melody in the scale, the other plays the same rhythm a third above or below. Because both notes are diatonic, the interval quality changes as the phrase moves through the scale - major thirds become minor thirds and back again - creating a naturally shifting harmonic color without anyone changing what scale they're playing. This is basic diatonic harmony applied at a high level of melodic sophistication.
Diatonic thirds in E major
Vibrato: the voice in the slide
Duane's slide vibrato is the defining feature of his sound. He applied it immediately and with a circular motion - not just side to side but with a slight rotation of the wrist that created a warm, wide oscillation more like a vocalist's natural vibrato than the mechanical vibrato of most slide players.
From a theory perspective, vibrato on a slide note does something that fretted vibrato cannot fully achieve: it continuously oscillates around the target pitch, never locking onto a fixed frequency. The result is that the note sounds alive and searching even when held for multiple beats. Every sustained note in a Duane Allman solo is in constant motion. There is no static moment.
Explore Duane's scales on the fretboard
Load E Mixolydian and find the major 3rd (G#) and the flat 7th (D). Those two notes together define the dominant 7th sound that Duane built his entire vocabulary around.