I think very initially it was indeed so, crackers were the ones doing the intros. But very quickly the efforts got split, most of the time, the person doing the intro was a different person, the person doing the music was another person and finally another person was the one doing the actual crack. I don't think it took very long for this split to be the norm, even though very early I'm sure there was individuals doing all three pieces alone.
They were different people, but they were in the same group and knew exactly what it was being used for.