Watch the Example 14 online guitar lesson by Brad Carlton from Guitar Lab: Boogie-Woogie
This example uses root position diatonic triads out of A mixolydian over an A bass. The chords are A, Bm/A, A7, Bm/A. You'll notice a different sound if you compare this example with example 6. The chords are the same but they are played in a different inversion.