This may be a little tough for some people to watch. In 1988, there was a tour called "Together Again" with Frank Sinatra, Sammy Davis Jr and — briefly — Dean Martin. It was supposed to be the three of them for the entire run culminating in a big performance taped for HBO…but after a week or so, Dean was gone, the HBO taping was cancelled and Liza Minnelli took his place for the remainder of the tour.
There are many stories about what happened — tales of Dino and Frank getting angry at each other — but clearly the underlying problem was that Dean wasn't Dean. His heart certainly wasn't in it. It was less than a year since his son Dean Paul had been killed in an air crash, and friends of the family said Dad just never recovered from that loss. Beyond that, his health and voice were poor. He did the performances he did, and several press events, with an attitude of "Why are we doing this?"
This clip purports to be the last ten minutes of Dean's last appearance on that tour. I don't guarantee that's so but he sure looks like a guy long past the time he should have retired. I suppose you can view this video — if you view it at all — one of two ways. It could be a sad spectacle of Dean at an age where he was just too old to be Dean Martin. Or it could be a testimony to the fact that his stardom and natural charisma would carry him through a performance. I imagine some in the live audience were willing to forgive his faltering and others weren't, especially considering the ticket prices.
Dean lived another seven years after this but did almost no performing. A friend of mine who knew him during his last years told me that it was on this tour that Dino realized there was no point. He had more than enough money and had long since stopped enjoying the job. More significantly, the friend said, Martin realized he'd become one of those performers he'd always mocked for not knowing it was time to get off the stage. Here's Dean before he realized that…