Lenny Kravitz Good Genes or Good Docs?

7/12/2009 2:01 AM PDT

Lenny Kravitz: Good Genes or Good Docs?!

Lenny Kravitz may party like a rock star ... but you'd never know it.

Here's the 25-year-old singer back in 1989 (left) -- and 20 years later, the 45-year-old version in London last month (right).

Are you gonna go his way?