Tony Bennett -- Good Genes Or Good Docs?

Tony Bennett is living the good life!

Here’s a 29-year-old version of the New York crooner at a photo shoot back in 1955 (left) and 61 years later ... the timeless singer -- who celebrated his 90th birthday earlier this month -- receiving The Entertainment Icon Award at an event in June (right).

The best is yet to come.

The question is...