In my previous article Minor vs Major, we briefly explored the use of the Major Scale over the I chord in your standard I-IV-V (1, 4, 5) blues progression. I had a lesson on Friday, during which my tutor revealed some interesting points about Relative Minors - "every Major has a Relative Minor". So what does this actually mean?

Lets assume we are going to improvise over a blues progression of A, D, E. The I chord here is the A, and this is the Key of our Blues song. Now, we could play the A-Minor Pentatonic or A-Minor Blues scale over this I chord, and all would sound great. However, as discussed in my previous article, it is often nice to play Major over this I chord. So we could play our standard Major Pentatonic/Blues shape starting at the sixth string root - A at the 5th Fret.

However, there is an alternative to using this shape. We can use the Minor Pentatonic/Blues shape to achieve the same goal - using A Major's relative Minor, F#. To find the Relative minor of the key we are playing in (A in this case), all we have to do is drop down three semitones to arrive at F#.  F# is the relative minor of A-Major. Confused? Relative Minors are always three semitones below the root. So three semitones back from A is indeed F#. When you play the Minor Pentatonic or Blues shape starting at F# on the sixth string, you are actually playing the notes from the A-Major Pentatonic/Blues Scale.

Lets study some pictures to see how this works. Pay attention to the notes in both diagrams - you will see that the notes are exactly the same for F# in the Minor Pentatonic/Blues as they are in the A-Major Pentatonic/Blues shape.

Fig 1. A-Major Pentatonic scale starting from the 6th String Root at A (5th fret)

Fig 2. The Minor Pentatonic scale, but starting from the 6th String at F# (2nd Fret) - The same notes as above, but the roots are in a different position.