Why can Song of Eternal Sorrow be adapted into a song?

Because this is a poem. Song of Eternal Sorrow can be adapted into a song because it is a poem, which was sung with music in ancient times, so it can also be adapted into a song in modern times. The central idea of Song of Eternal Sorrow is to criticize the love tragedy of Xuanzong in Tang Dynasty and praise their eternal love. The whole poem is very artistic. The first is the selection and application of original historical materials.