The only person of any 'celebrity' I've seen in concert was Billy Joel, back during the Storm Front tour (which I think was 1990).

I've seen some other bands, but they wre all the 'college band' type and probably not known outside Indiana.

Musicals I've seen more of, in the last 14-15 years or so:
Phantom 3 times
Les Miz once
and most recently
Miss Saigon

Otherwise 'celeb' encounters have been brief things, and sometimes I've walked away with autographs (I think I talked about this in another thread...)