[dalbasal]

In part, this is probably because old Persian poetry/song traditions were more modern, compared to english poetry from the same period. They had a strong, very old literary tradition. The English didn't, until a bit later. Chaucer was part of building it.

The musical/poetic sensibilities of old/middle English are way too different to ours.

The Bible (especially in Hebrew) can also easily be plagiarized, and you'll find lots of lines/poems that work "as is" in a pop song.

Eg, rivers of babylon, boney m.