In Sumer/Akkadia/Babylonia/Mesopotamia (sorry, I always confuse them with each other) we have oldest writings ever and oldest songs ever, simply because they used burned clay to write stuff and that survives the longest.
Other cultures either didn’t write stuff down, or they did, but on less resilient material. For example Egypt civilisation is probably older, but they used papyrus, which survives less than clay.
edit: I guess I am wrong, see below
So this song is not really “oldest song ever”, that is a hyperbole, but oldest surviving writing of a song.
The civilizations in ancient Egypt and Mesopotamia invented writing around the same time. Sure, hieratic or cursive hieroglyphs in ink on papyrus is less durable than cuneiform impressed in clay (which more often than not, was not intentionally baked). But the Egyptians also carved and painted hieroglyphs in/on stone and that's plenty durable. Also, papyrus in Egypt survives much better than elsewhere because of the hot and dry climate. There's writing on papyrus that's 4,500 years old.
The disagreement over whether writing was first invented in Egypt or Mesopotamia is mostly one of delineating writing and protowriting. There's plenty of examples in both cultures of markings from both sides of that divide, wherever it may actually lie.
Proto-writing in Sumer predates proto-hieroglyphs in Egypt. It is thought that writing in Egypt was inspired by the ‘idea’ of written communication in Sumer
Gunung padang claimed older than giza and mayan pyramid by some archeologist. If this true, java culture by times are much more advanced than the middle east or latin area. Including music.
Other cultures either didn’t write stuff down, or they did, but on less resilient material. For example Egypt civilisation is probably older, but they used papyrus, which survives less than clay.
edit: I guess I am wrong, see below
So this song is not really “oldest song ever”, that is a hyperbole, but oldest surviving writing of a song.