String Theory is a bi-annual publication intended for guitarists who are interested in all aspects of music theory, specifically as it pertains to the guitar. 

String Theory: The Mixolydian Pentatonic Scale was originally published in the Fall 2018 edition of Open Position.

“My best songs come from making a lot of mistakes and playing a lot of garbage.”

~ Eric Johnson

Eric Johnson is a gifted and unique guitarist. Born on August 17th, 1954 in Austin Texas, Eric was influenced by guitarists Eric Clapton, Chet Atkins, Wes Montgomery and Jimi Hendrix to name a few. Johnson recorded two albums ‘Seven Worlds’ and ‘Tones’ before finally hitting the nail on the head with the album ‘Ah Via Musicom’ released in 1990.

In 1991 the single “Cliffs of Dover” from ‘Ah Via Musicom’ earned Eric a Grammy Award for Best Rock Instrumental Performance and ‘Ah Via Musicom’ went platinum. Eric has gone on to record a total of nine records of his own including the album ‘Up Close’. Released in 2010 the album is decidedly different in that Johnson eases up on the reins a bit and plays with more abandon than in previous albums where his desire for perfection abounds.

“I wanted to be successful, not famous”

~ George Harrison

George Harrison was rarely allowed more than one or two songs on any given Beatles album, on Sgt. Pepper’s he contributed only one. The tune ‘Within You Without You’ is a definitive Harrison offering exemplifying the Beatles guitarists attraction to the Sitar and Indian music in general. His choice of scale for the melody is essentially Mixolydian which is somewhat surprising considering the bluesy nature of the Mixolydian mode. The way in which Harrison interprets the mode is more like a pentatonic version of the scale. This sound I refer to as the Mixolydian Pentatonic Scale.

The Mixolydian Pentatonic Scale is basically a Mixolydian scale minus the 2nd and 6th degrees. In the key of C it would be as follows:

C E F G Bb or Root 3rd 4th 5th and b7th.

The five note scale consists of a C7 arpeggio with an added perfect 4th degree creating the sus4 tension and resolution on the chord C7 but can also be played over other C major chords such as a C power chord, Cadd9, C7sus4 etc.

In the Intro to Eric Johnson’s tune ‘Venus Isle’, Johnson repeatedly arpeggiates the Mixo Pentatonic scale creating a middle eastern style texture in the process. He uses it again in ‘Nothing Can keep Me From You’ and from his new album ‘Up Close’ the tune ‘Fatdaddy’. The scale can be heard quite a bit in Johnson’s melodies and solos, he tends to be drawn towards that type of sonority in his playing. George Harrison’s melody to ‘Within You Without You’ is another example of the Mixolydian Pentatonic scale and is used in a similar manner and with the same affect as Eric Johnson’s Venus Isle.


The soundscape created with this particular scale is one of spaciousness

and optimism. It has a positive eastern influenced vibe about it and its easy to hear why these two guitarists in particular gravitate towards its color and inherent musical nature.

In the PDF file below the Red/Blue roots shown are the root notes of the Mixolydian Pentatonic scale. The Mixolydian Pentatonic scale consists of a Root, 3rd, 4th 5th and b7th. It can thought of as a Dom7 arpeggio with an added perfect 4th. Experiment with it over any major chord type especially Dom7th, Dom7sus4, and power chords or over any Mixolydian chord progression.