As a suggestion for the 7.12.17  12:52 pm person, I guess you can settle for 6/8 if you want one sig that encompasses everything. As in there are always 6 quaver beats in the bar but not necessarily grouped in 3 crotchets/quarter notes/whatever (ie 3/4). Essentially like a musical lowest common denominator if that makes sense?
that seems mathematically true, but in reality 6/8 is almost always grouped in 2 groups of 3. in reality 6/8 almost always means 2/1-and-a-half but that would be a mindfuck to write on a piece of paper. if it's 3 groups of 2 it almost always is written as 3/4. although there are many songs that borrow back and forth between the two feels. especially in west africa