A well-known (if not universally liked) example is the first few minutes of Tubular Bells. It cycles through 7/8, 7/8, 7/8, 9/8 over and over. 7+7+7+9 = 30. The bass part is played in another time signature, but it also cycles through a pattern adding up to 30 beats, so it all comes together. Music is just mathematics!