An important rhythm technique used in many styles of music is the Percussive Strum. This is achieved by forming a chord shape with the left hand and placing it on the strings, but without pressing down on the frets. A percussive strum is indicated by using an X in place of a notehead.
This technique can be applied to any type of chord. The following example features percussive strumming with root 6 bar chords. Wherever percussive strums occur, release the pressure with your left hand, so that the fingers lift up off the fretboard but still remain in contact with the strings. Keep the bar chord shape so you are ready to press down again to play the next chord as soon as it occurs.