Ruṇṇasutta

“Ruṇṇamidaṁ, bhikkhave, ariyassa vinaye yadidaṁ gītaṁ. Ummattakamidaṁ, bhikkhave, ariyassa vinaye yadidaṁ naccaṁ. Komārakamidaṁ, bhikkhave, ariyassa vinaye yadidaṁ ativelaṁ dantavidaṁsakahasitaṁ. Tasmātiha, bhikkhave, setughāto gīte, setughāto nacce, alaṁ vo dhammappamoditānaṁ sataṁ sitaṁ sitamattāyā”ti. Pañcamaṁ.

“Singing is regarded as wailing in the training of the Noble One. Dancing is regarded as madness. Too much laughter, showing the teeth, is regarded as childish. So break off singing and dancing; and when you’re appropriately pleased, it’s enough to simply smile.”