When playing Rock "n" Roll or Blues styles, guitarists commonly use power chords that keep the root note the same, and the other note alternating between the 5th, 6th and flattened 7th degrees. These chords can be referred to as Rock "n" Roll chords, or simply Rock chords.
Here are the two-string Rock chord shapes for A, A6 and A7. In all three chord shapes only the 5th and 4th strings are strummed. The open 5th string is the root note (A).
A
A6
A7
The open circle with the number 1 inside it indicates that you keep your 1st finger in position even though that note is not being played.
Play the following chord progressions using the above rock chord shapes. Use eighth note strums and only play the 5th and 4th strings. When playing power chords, it is common to use only downstrums, as this achieves the best sound
Here are the previous examples as a two bar pattern.
Now learn the two string rock chord shapes for D, D6 and D7. Play only the 4th and 3rd strings.
D
D6
D7
Play the following two bar chord progression using the D rock chord shapes. Use only downward eighth note strums playing the 4th and 3rd strings only.
Here are the two string rock chord shapes for E, E6 and E7. Play only the 6th and 5th strings.
E
E6
E7
This two bar chord progression uses the above rock chord shapes. Play only downward eighth note strums.
Play the following 12 bar Blues in the key of A using rock chords. When there are two bars of a chord, substitute a two bar pattern. For the A chord in bars 1 and 2, 3 and 4, 7 and 8, use the two bar pattern in example 63.2. For the D chord in bars 5 and 6, use the two bar progression in example 63.3. Try to play this 12 bar Blues from memory. If you hope to play in a band or even jam with your friends, the ability to play songs from memory is an important skill to develop.