And good voices remain good voices, however much older the singers get.
Well, sort of!
I had the pleasure of seeing Petula Clark sing when she was in her 70's and she was brilliant. No noticeable loss of range or power - and she sang for two hours.
However, other singers don't fare so well, and it is, I think, down to how they look after themselves. I'm not going to post it here, but there are videos of Liza Minnelli (who whether you like her or not, could belt out a tune and hold it very well in her prime) performing more recently, and well basically she shouldn't. The loss of her talent I am sure is down to many years of abuse - smoking, drugs, etc.
Other voices, more notably male singers (in my experience) take on an edge of frailty that makes their singing somehow more touching and affecting. Thinking the late Johnny Cash here, amongst others.
