I listen to classical music on a local radio station and midevieal music is played enough, but I don’t think I’ve ever heard music composed during the Roman Empire or the Greek Civilization. I’m sure that people in ancient times had musical instruments and knew how to write music, so the absence is interesting
Did no pieces survive, were they never written down or are they just not particulary interesting?
Very little survives from before about 1000 A.D., most of it only fragments. On top of that, no one is particularly confident about how to interpret the system of musical notation in use at the time (a problem that persists well into the Renaissance).
The answers given aren’t as surprising as they might be, when you look at music from a less Euro-centric point of view. Western european music from the twelfth century onwards is pretty much unique, in that it developed a systematic method of notation that can be understood without the necessity of an inherited aural tradition alongside it. Even just slightly earlier European chant notation (such as the tenth-century neumes here) requires some knowledge of the melody to be passed on along with the notation, and obviously this has been lost. It would be surprising if earlier notations did not have a similar partial role.