They might be identical every time! quote Steve Shaw ,
you are right if they are identical ewery time, that is due to lack of thought, ABOUT how the riff is played which was one of my earlier points, even if the notes are the same ,they should be played with different emphasis or dynamics, that is partly what makes better musician ship.
it is not what it is called that matters, but how its played, do you think Richards or Wyman worried about what it was called?