People's singing voices don't work that way. Some people have bigger ranges than others, and generally your range only widens with singing lessons. My range was pushed up and down greatly by singing teachers. Vocally most people don't reach their peak until late their late 30's and then into their 50's. But after 63 it's all down hill. It's to do with getting old and nothing esle, and there's nothing you can do about it. Some people can sing well past 63, but they are lucky. Infact Karen didn't have a huge range, nearly all Carpenters songs are recorded between bottom E (below middle C) and A above middle C. And I mean nearly all, it least 75%. Infact the best way to find which key the Carpenters are singing in is to place the bottom and top notes of the song on those 2 notes!