Watch the Applying The Box Am7 - Dm7 - F9 - E9 online guitar lesson by Robbie Calvo from The Power of Five

This is a 10 bar minor blues where we are mixing minor 7th chords and dominant 9ths.

The default scale that most players would reach for over this progression would be A minor pentatonic scale. There is absolutely nothing wrong with that but there are some pretty horrendous tones that can occur if you're not careful over the F9 and E9 chords.

What we are going to do is show you how to break the box using the box in several places on the fretboard. We'll use A, E and B minor pentatonics over the Ami7 for example to open up the tired old sound of the one scale fits all approach. We'll play D, A, E minor pentatonics over the D chord.

The most exciting part of this section for me though is to show you that D and C minor pentatonics outline the F9 chord change beautifully and consequently C# and B minor pentatonics outline the E9 chord.

Let's analyze why those choices work.

Ami7

Scale Tones A-C-D-E-G = R-b3-11th-5th-b7 = A Minor Pentatonic

Chord Tones A-C-E-G = Ami7 (4 scale tones)

Scale Tones B-D-E-F#-A - 9th-11th-5th-13th-R = B minor

Pentatonic (Great on Exts.)

Chord Tones A-C-E-G = Ami7 (2 scale tones)

Scale Tones E-G-A-B-D - 5th-b7-R-9th-11th = E minor Pentatonic

Chord Tones A-C-E-G = Ami7 (3 scale tones)

Dmi7

Scale Tones A-C-D-E-G = 5th-b7-R-9th-11th = A Minor Pentatonic

Chord Tones D-F-A-C = Dmi7 (3 scale tones)

Scale Tones D-F-G-A-C - R-b3-11th-5th-b7 = D minor Pentatonic

Chord Tones D-F-A-C = Dmi7 (4 scale tones)

Scale Tones E-G-A-B-D - 9th-11th-5th-13th-R = E minor Pentatonic (Great on Exts.)

Chord Tones D-F-A-C = Dmi7 (2 scale tones)

F9

Scale Tones D-F-G-A-C - 13th-R-9th-3rd-5th = D Minor Pentatonic

Chord Tones F-A-C-Eb-G = F9 (4 scale tones)

Scale Tones C-Eb-F-G-Bb - 5th-b7-R-9th-11th = C Minor Pentatonic

Chord Tones F-A-C-Eb-G = F9 (4 scale tones)

E9

Scale Tones C#-E-F#-G#-B - 13th-R-9th-3rd-5th = C# Minor Pentatonic

Chord Tones E-G#B-D-F# = E9 (4 scale tones)

Scale Tones B-D-E-F#-A - 5th-b7-R-9th-11th = Bminor Pentatonic

Chord Tones E-G#-B-D-F# = E9 (4 scale tones)

You'll also notice that the E minor pentatonic has some really nice tones against all of the chords and this scale is well worth exploring as an option over the whole progression.