Note: Please read article post Understanding Scale Modes to help prepare for Pentatonic Scale Inside The Major Scale On Guitar
This article post is about the scale myth and confusion of how the Pentatonic Scale relates to the Major Scale. The biggest confusion is what key am I really playing in when I am working with two types of scales (Major Scale Versus Pentatonic Scales) and how do they interact and relate to each other? In a live improvisation playing situations where your not sure of what key your playing in. The first thing your usually going to do by ear is find that common Minor Pentatonic Scale Box and see what chord changes are being played. You usually are not going to try playing any major scale 1/2 step notes until you are absolutely sure what major scale key your playing in.
If your playing with Blues and Rock Players unto Jazz and Classical Players. The scale key that is called out may be very different unto the class and school of musicians that your playing with. Jazz and Classical players are usually more schooled in music theory and they relate the key to the key signature of the Major Scale. A lot of Jazz players are more concerned with modes and the tonal center. Blues and Rock players on the other hand relate the key to the Minor Pentatonic Scale (The bordered notes shown in the fingering on the first row). Blues players usually stay in Pentatonic and Blues Scales (Major scales are a taboo). The I of the I , IV, V chord progression dictates were the Minor Pentatonic Key lies and that is how they relate the key. Rock players use both but more in the pentatonic and blues scales.
Here is the big kicker, three different Pentatonic Scale Keys can be super imposed on the major scale. The Minor Pentatonic Scale can be super imposed on the three minor modes of the major scale – (vi) Aeolian Scale or Natural Minor Scale, (ii) Dorian Scale, (iii) Phrygian Scale (1st row of the fingering diagrams). The chord progression order of the chords being played is what’s going to rule this relationship. The (G Major Triad Chord Scale Chart) shown below shows the major chord scale order and what relates to the scale fingerings below.
The (Diagram – Fret 5 A Dorian Scale/ A Minor Pentatonic Scale) is the most common relationship found and it’s usually when the IV chord is Major. This one is common in a lot of I, IV, V. Blues & Rock Progressions. The next commonly found relationship is the Aeolian Scale/ Minor Pentatonic Scale. This usually is when the IV chord is minor.
The least common relationship is the (Diagram- Fret 7 B Phrygian Scale / B Minor Pentatonic Scale). This can happen if the II Chord is Major. The simplest overview of all of this technical jargon is to analyze the chords that are being played within the Minor Pentatonic Scale fingering. This gives you a clue to the notes of the major scale mode and what major scale key your playing in.
If a guitar player with a good ear has practiced both types of scales, they can usually find their way around both scales relationships easier. You can never stop getting better at scales. The more you practice and apply yourself to play each of these scale relationships in your solos. The better your is ear is going to become in adapting playing to different types of chord progressions. Guitar Analyzer Software can instantly display how the three pentatonic scales can fit inside every major scale key as shown below.
G Major Triad Chord Scale Chart