Valmiki Ramayana Kishkindha Kanda Sarga 28 Shloka 36

वनेषु in the forest, षट्पादतन्त्रीमधुराभिधानम् the sweet humming bees like the music of string instruments, प्लवङ्गमोदीरितकण्ठतालम् the croaking of frogs, मेघमृदङ्गनादैः rumbling of clouds like beating of drums, आविष्कृतम् started, सङ्गीतम् musical concert, प्रवृत्तम् इव as if commenced.

'The sweet humming of bees like the music of string instruments (Vina), the croaking of frogs, the rumbling of clouds sounding like the beating of drums make it appear as if a musical concert has started in the forest.