Watch the Variety Show online guitar lesson by Brad Carlton from Chord Studies: Slash Chords Vol. 2
This is a nice, easy pedal tone slash chord progression with the open fifth string as our pedal. So we play our A and then move up a whole step to B/A. Moving up a minor third (three frets) we get D5/A followed by D/A. Now we switch our chord shape and run through the progression again, adding a D on the E string for the last chord to get a bit of variety in the voicing. Notice how this little change makes the progression feel more complete.