From Du Mu's (
杜牧, Tang dynasty)
《泊秦淮》:
烟笼寒水月笼沙,
夜泊秦淮近酒家。
商女不知亡国恨,
隔江犹唱后庭花 - 'Mist veils the cold water, moonlight veils the sand; I moor at Qinhuai by the taverns. The singing girls know not the grief of the fallen nation - across the river they still sing Flowers of the Rear Court.' The poem names the Chen dynasty's farewell tune as a warning: the late Tang is repeating Chen's decadence.