By that video, he had been taught how to modify his singing presentation. They might have even used lip syncing to make sure they got the right sound with a better image.
In the 1960s, he basically looked like he was in pain when he sang.
Mostly you can ignore those debts, with a very few exceptions. Although it’s not legal, some collection agencies will imply that you are responsible for a dead parent’s debts, but do not start paying them because once you do, you can be held responsible for it.