This sentence uses the method of image description to express a wonderful scene through the action of the fairy touching the piano and the aftertaste of the piano sound. The gentle and meticulous movements of the fairy make the strings emit melodious music. These piano sounds echoed in the mountains, and the sounds spread like ripples, creating a quiet and mysterious atmosphere. The description of the lingering sound around the mountain also implies the persistence and influence of the piano sound, as if the fairy's piano sound can reverberate in the mountain for a long time, giving people a touch and feeling of the soul. The whole sentence shows the magic of fairy fiddling and the charm of music by expressing a wonderful music scene.