Elton John went from having no hair on the top of his head in his 20's to having lots of different types of hair throughout his adult life. You can tell when he has a wig most of the time because there isn't a clear part on his head. The hair just kind of sits there, using his head as a rest stop.
It was clear that his front hair was thin and receding fast. Yet about 40 years later here he is:
Some do argue that he has hair plugs too. I wouldn't be surprised if that were the case.