Notes:

• Mixolydian Mode (or the "Dominant Scale"), is the same as the major scale, but with a flat 7.

• There is only one dominant 7 chord in the diatonic series, which makes it rather unique. Despite this, I7 - IV7 chord progressions are very common in blues and rock.

• Another unique thing about dom 7 chords is that they have a tritone in them. (A tritone = 3 whole steps = b5 interval.) Tritones are quite dissonant and give dom 7th chords a somewhat jarring quality.

• The backing track is in the key of G and I play a I7 - IV7 vamp (G7 - C7). I add a Sus4 to both chords briefly for interest.

• We'll start super easy; by humming just one note!

• You can play a lot of different things over a dom 7 chord, perhaps because of the built-in dissonance of the triton in the chord. So, you can play both Maj and Min pentatonic scales!

• Because this is not a diatonic progression, you can not use a single 7-note scale over both chords. But, you can play G Mixo over the G7 and C Mixo over the C7.

• I find it easier to think of the above 2-scale solution as just flatting the 3rd of G Mixo when playing over C7. (This would then become G Dorian, which is the same notes as C Mixo.)

• Try making your own variations of these licks and lines.

• Try playing the lick up or down an octave.

• Try harmonizing melodic lines in 3rds or 6ths.

• Try playing it on different parts of the neck.