Music notation does not express concurrency easily. It expresses parallelism easily.
It can do this each part can be played in isolation - in other words, they are pure.
It can do this each part can be played in isolation - in other words, they are pure.
For "concurrency" think of the operation, "You go off and take care of that. I'll take care of this. We might meet up later."
For "parallelism" think of performing a sequence of operations in lock step, while standing next to each other.
That these are independent can be seen in programming when you compare multi-threaded programming (concurrent but in no way parallel) with programming for the GPU (very parallel, but none of the type of concurrency that I'm discussing).
Returning to music notation, it is like a GPU - everything goes in lock step. Stuff happens simultaneously, but not independently.