I was looking at this hand-written short score (to be completed by other arrangers):
The only thing that strikes me about it (maybe there should be others) is there is no written time signature. Why?
Then I had the following thoughts. Please correct me if I'm wrong.
The beaming notation already implies where the beats are. And the bar-lines separate and indicate how many beats per measure. So in essence, you could infer exactly what the time signature was? It also seems like the time signature changed several times, based on this premise.
In other words, most (perhaps all) time signatures are redundant; because they are directly implied through the other notation (especially if ties and beams are used rigorously).
This would also mean a performer wouldn't even need to see a time-signature, as long as he/she is reading ahead and taking note where the beams and ties are- he/she will know when the beats occur.