Minor Pentatonic Scale over Major Chord Progression

Hi Barrett,
I just bought your book "chord-tone soloing" and I have a question with the first chapter. You are a playing A to D which is just a I IV chord progression in A major. Why is it that you are using the minor pentatonic scale and not major scale? Would both scales work? A marriage of major and minor? Your using the C note to lead in to the A major chord. Is that just considered a passing tone? I guess this all just boils down to why does the minor pentatonic scale work over an exclusive I IV V major chord progression? Any help would be great. Thanks a lot for your time!
Steve

Hi Steve,
To your questions:
"Would both scales work?"
Yes, both major heptatonic and minor pentatonic scales would work, depending on the stylistic context.

"Your using the C note to lead in to the A major chord. Is that just considered a passing tone?"
Yes, the C notes on track 3 would be melodic passing tones in harmonic common practice. (See Piston, Harmony, 5th edition, p.116.)

"I guess this all just boils down to why does the minor pentatonic scale work over an exclusive I IV V major chord progression?"

This is a stylistic sound that is best considered outside common practice harmonic theory. Most guitarists have heard plenty of rock and blues music where minor over major happens all the time, so I start the book with it. It's a type of dissonance that people are accustomed to now but might have been strange during the "common practice" era of harmonic theory in the 18th and 19th centuries.

Minor-based notes over major harmonic progressions (interpreted into a series of dominant chords) are usually attributed to Western classical harmony blending with African influences to give birth to blues, ragtime, jazz, gospel, and similar styles.

The Chord Tone Soloing book has three parts. On page 2 it says "Part One is a very simple preview to show you where the book is going." It helps everyone---including beginners who may have never heard of a key center or don't know the difference between major and minor chords---to understand what's coming. This means you're ahead of the game a little, so that's good.

The examples in Part One just show how important it can be to choose the right note when the chords change, even when playing within a single scale. They do not teach any new information for most players. I use A minor pentatonic in 5th position because even beginning guitarists are likely to know the fingering already.

Right from the beginning we get a non-chord target tone, in Chapter Two. This shows that while we need to know where chord tones are, they will not always be our targets.

Analysis of chords and progressions comes after the foundation of scales, chords, arpeggios, and diatonic harmony. Later we go back and see how blues and rock conventions let you play minor sounds over dominant 7th chords and major triads. Starting after p. 74, non-diatonic notes of this type appear throughout the rest of the book.

It sounds like you know some theory already, but please make sure to read all the introductions and all the text in the book as you go. I tried to make it short, but sometimes people skip the words and go straight to the examples. For this book that can cause problems because we're learning concepts, not licks.

Thanks very much for the excellent questions.
Barrett