
This painting is located to the right of the niche on the back wall of the main chamber. The Sakra Prasna Sutra describes the event depicted, wherein a gandharva with five hair knots plays music and chants for the Buddha. The gandharva is seated to the right of the Buddha. He holds a harp in his right hand and raises his left hand high with the palm facing up, as though in the midst of exuberantly plucking the harp. The face of the gandharva is damaged, but his graceful gesture is still clearly visible.
For more details, go to the Encyclopedia of Buddhist Arts: Caves R-L, page 539.