Less now, but I passed 70 last year, and we're planning an open-air (free...) gig for end of May. Demographic of our 'fan base'..? Anyone that wants a decent night out listening to our repertoire, which is quite varied..! All ages, mixed gender, mostly French (but we don't ask for identity anyway, so could be anyone...).
We have a couple of mini-festivals and bars that invite us to play occasionally, so it's whoever happens to be there that evening. We play for our pleasure, and don't 'target' anything, really. We just want everyone, including ourselves, to have a good evening, s'all.
Age..? I can't see it mattering much, and 50-odd is no age at all.