I’d say no. That’s not being an audience member.
Then I’d say 1K-2K, altho it could be quite a bit lower. I figured out early on in my life that it made more sense to be paid to listen to music than to pay to listen to music.
What about someone working as a concert reviewer?
What, to you, does it mean to be “an audience member”? What if I didn’t pay to get in?
I never had the pleasure of seeing them play live, but Howard Levy was a regular at the cafe I worked at in the mid-90s, so I was sometimes treated to a little solo harmonica at the cafe after hours. 
I had no idea who he was when I first met him – just asked him for some harmonica advice as the cafe closed down, as I always saw him there fiddling away on his custom-made-by-Joe Filisko diatonic Hohner, while writing some music, and, next thing I know, it turns out this guy is one of the world’s greatest diatonic players. Very nice guy.
What about live music in bars and clubs?
If you went there to listen to the music, I’d say yes. If it was incidental to something else you were there for, probably not.
I said 600-1000; I’ve got a BA in Music and went to a lot of noon recitals, symphony and brass quintet concerts. I was also active in bardic performance in the SCA for about ten years and went to a ton of multi-hour bardic circles.
Church every Sunday for many years. I’m thinking that wasn’t what you wanted. But it’s true. I grew up singing because I was exposed, over the years, to a lot of live music.
600-1000 for me, although it’s possible that it’s merely 301-600. I’ve been to over 100 concerts and that’s just the acts that I remember, in my adulthood, that I wanted to see, so I’ve probably forgotten some stuff from my childhood and/or some stuff that I was dragged to (which I still count as deliberate attendance since I wasn’t kidnapped or anything.)
I said 11-30. It might be a little low but the number is easily in single digits depending on how we count. I don’t go to see live music in general. I’ve never bought a concert ticket. There was a Woodstock style punk/alternative festival with camping on site in the farmer’s field that I attended. I never got close enough to see a band actually on stage during it. It was effectively a camping trip with a radio station playing live cuts in the background. There was another music festival I got in free because I worked the gate. My seeing music while I was there and off the gate was limited to minutes.
Even when I’ve gone to intentionally see bands in small clubs I only really pay close attention for bits of the time. I get bored just watching people make music after a bit and wander off elsewhere in the bar. I like music. I approach it more like a movie soundtrack to life. It goes in the background. I don’t particularly care to watch musicians make it. I certainly don’t want to pay to watch them do it.
Do DJ’s count as “live”? I’ve gone to many many a club/fest to see certain DJ’s who play music that they produced (as well as others’ music) most of which would be completely impractical to “play” with “instruments”
I voted 601-1000, but on second thought I think I qualify for the 1001-2000 bracket. Besides “big name” acts, I had friends in bands that played local clubs and I went to see them often.
We’ve almost certainly crossed paths. I go to around 80 shows a year and have been seeing live music for decades. Mostly jam bands, blues, blue grass and funk.