Before I answer, I would like to preface with the statement. I don't mind at all their voices are a little strained after 20 years. It would be supernatural if they weren't. I'm glad I listened to them in their prime. With all that out of the way, I am going to say Paul McCarney's voice is much different these years. Aretha Franklin is another whose vocal cords are tired. Mariah Carey was never one of my favorites but the last time I heard her, well, I'll leave it at that.