I watched Sir Elton John on BBC Two in concert the other night, his piano playing was great and his band were fine, but his voice was quite different to the Elton John I remembered, all deep and 'growly' nothing like his old voice !
Sir Paul McCartney's voice isn't what it used to be either, while Cliff's last album sounded to me as if his voice isn't quite what it was
they CAN all still sing...but it isn't the same sound anymore due to age...
I think what happens is the top of their vocal range goes....hence they don't sound the same singer !
I recall years ago a school chum's father who was a big Bing Crosby fan telling me;
'he's rubbish now, his voice went about ten years ago and he's just 'croaking' now compared to his older sound...' (!!)
seems a number of 'our era' stars are now reaching that stage too - Time gets to everyone and maybe it's wise to go out with dignity on a high...