"... fan's recordings of 10k concerts..."
59-year-old Aadam [sic] Jacobs made his first recording 42 years ago in 1984 when he was 17.
He would have had to average 238 recordings/concerts per year — nearly 5/week — over those 42 years to accumulate 10,000 of them.
https://en.wikipedia.org/wiki/Aadam_Jacobs
He began to attend and record 15 concerts each month, and has said "It went pretty quickly from just being an occasional thing to something I did far too often."
So his average is every other day. Also, most concerts / shows have more than one act. I went to an MF DOOM show back in the day at a small club with FIVE opening acts, and then DOOM had THREE more openers in his set time. That's 9 total acts on one night. Even the sprawling wu-tang tour last year had run the jewels as an opener.
Wu-tang + run the jewels sounds like a hell of a show.
they may count the opening acts as separate concerts
This is disposative.
Look it up
They're unlikely to find much unless they instead try “dispositive”.