Once you've got a handle on forming major and minor barre chords on the guitar, it's time to add some more depth and variety to your playing. Dominant 7th chords have a sharper, more complex sound than do straight major chords. Fortunately, switching to a barre dominant 7th chord from an major barre chord based on E, is just as easy as switching from a major to a minor barre chord — you just lift a single (although different) finger.
For example, to change an F major barre chord into an F7 barre chord:
Finger an F major barre chord.
Remove your fourth finger from the 4th string.
The first-finger barre now frets the chord’s new note.
Now try playing the simple progression shown in the following figure using major and dominant 7th barre chords. Playing the progression in this figure in different keys is as simple as starting in a different location from the third fret and moving the same distance. From wherever you start, simply move up two frets for the second chord, up three more frets for the third chord, and then up two more frets for the fourth and last chord.
