Not a fan of the vast majority of The 1975's music, but what I seen of them at TRNSMT last year was terrific. Would have stayed for the whole thing if I wasn't a bit iffy about getting home.
A marketer could technically know, if they have their tracking on Ticketmasters sales page...
IME though and assuming ticket master allowed it, it would only be that agency who would have access to the data, it certainly would not be accessible to any old punter with access to Google Adwords!