Doc Severinsen is 82 today, and no finer example of outlandish talent meshed with professionalism exists in any field. I was fortunate to play a gig with Doc in my previous life as a musician, and it's one of my fondest memories of that time. It was the next-to-last week of Johnny Carson's tenure on the Tonight Show, so he couldn't get Friday night off to fly to Virginia for the gig. Doc played the show and took the red-eye to Dulles. When I walked in for the dress rehearsal at 9:30 Saturday morning, he'd already been there for at least half an hour, warming up. (So, yes, I have seen Doc Severinsen dresed as a normal person.) He played the rehearsal, took a nap, and played his ass off that night. He was charming and generous to the mostly amateur musicians. I hope he's around and active for a while yet.
Gustav Mahler was also born on this data in 1860. Him, I never met.