How To Play Djembe
This one's easy. Place either hand firmly in the middle of the drum resting on the face. Now play a tone with the other hand. The drum's natural resonance is muted and you get a shorter sound without any ring.
You can also vary the pitch of the muted tone by pushing harder or softer on the face. Try playing a few muted tones with one hand while pushing harder and softer on the face with the other.
The muted tone is shown in the charts with a 'gi' or 'di'. Gi is played with the black hand i.e. the red hand is resting on the drum, and 'di' is played vice versa.
M U T E D T O N E
Try this exercise to hear it in practice.
Play a bass note with the 1st hand. Then on count 4 play a bass with the 2nd hand, but this time, when your hand hits the drum, hold it there (don't let it bounce off). Now play the muted tone with the 1st hand. It looks like this: