Short answer: sometimes. Over a dominant 7 chord in a blues, yes, and the clash is the whole point. Over a plain major or major 7 chord, the minor pentatonic built on the chord’s root sounds wrong, because it’s wrong.
The usual advice at that point is to learn the major pentatonic. I don’t think you need to. You need to move the minor pentatonic you already know, and once you see where it goes, it covers far more major chords than you’d expect.
Why it works over a blues
Play the A minor pentatonic box at the 5th fret over an A7 chord. The chord has a C# in it. Your scale has a C. Those two notes are a semitone apart, and on paper they shouldn’t sit together.
In a blues they do. That rub between the flat 3rd and the major 3rd is the sound of the style. Players lean on the C, bend it slightly sharp, or hammer from it straight up to the C#. The major 3rd is always one fret above the flat 3rd, so the fix is never far away.
Here’s the move in its simplest form. Hammer from the flat 3rd to the major 3rd on the G string, then land on the root:
So yes, minor pentatonic over a major chord works in a blues. It works because the dominant 7 chord and the blues tradition both tolerate that clash. Take either one away and it stops working.
Where it falls apart
Put that same A minor pentatonic over an Amaj7 in a ballad, or an A major chord in a country tune, and it sounds like a mistake. The C fights the C#, the G fights the G#, and there’s no blues context to excuse either of them.
This is where most lessons tell you to switch to the major pentatonic. That’s not bad advice, but it hides something more useful. The A major pentatonic contains exactly the same notes as F# minor pentatonic. You already knew how to play it. You were just putting it in the wrong place.
One box, four chords
Here’s the part I find more interesting. Don’t move the box at all. Keep the A minor pentatonic at the 5th fret, and change the chord underneath it.
Over Am7
Where you learned it. R, b3, 5, b7.
Over Cmaj7
From the 6th. Plain major, no clashes.
Over Fmaj7
From the 3rd. Maj7 and 9 come free.
Over Bbmaj7
From the 7th. The #11: Lydian, fusion.
The shape is identical in all four. Your fingers don’t learn anything new. What changes is what each note means against the chord, and that’s what your ear hears. Over Bbmaj7 the same box you’ve played for years suddenly sounds like fusion, not blues.
That gives you a simple rule for major 7 chords. A minor pentatonic works when you build it on the chord’s 6th, its 3rd or its 7th:
- From the 6th (A minor over Cmaj7): a plain, sweet major sound.
- From the 3rd (A minor over Fmaj7): the major 7th and 9th, with no extra work.
- From the 7th (A minor over Bbmaj7): adds the #11, the Lydian sound.
Turn it around: what to play over an A chord
If the chord is fixed and you want to know where to put your box, run the rule in reverse. Here’s every minor pentatonic that works over an A chord, and where its box starts:
| Chord | Minor pentatonic | Box at fret | Sound |
|---|---|---|---|
| A7 (blues) | A minor | 5 | The b3 rub. Blues. |
| A7 or Amaj7 | F# minor | 2 or 14 | Plain major. Country, pop. |
| Amaj7 | C# minor | 9 | Maj7 and 9. Modern, open. |
| Amaj7 | G# minor | 4 | Adds the #11. Lydian. |
| A7 (altered) | C minor | 8 | b9, #9, b13. Jazz tension. |
The last row is a bonus. Over a dominant chord that’s about to resolve, the minor pentatonic a minor 3rd above the root gives you the altered sound jazz players spend years on. It’s the same shape again.
Try it with a looper
Record one bar of Bbmaj7 and let it loop. Play your A minor pentatonic box over it for two minutes and don’t try anything clever. Then swap the loop for Fmaj7, then Cmaj7. Same box, same licks, three different sounds.
That two-minute test teaches more than any chart, because your ear does the work. Once you’ve heard it, you won’t think of the minor pentatonic as a beginner’s scale again.