Only two that I’ve actually walked out of...
Hawkwind - York Barbican mid-80s. Had just driven from Gloucester for the weekend to be met by my best mate telling me he had a special treat, tickets for Hawkwind. I was tired, hadn’t seen him for a few weeks and after about 40 mins of the godawful racket, we looked at each other and said in unison , “Beer?” Didn’t go back.
Wishbone Ash - 50th Anniversary - Brudenell Social Club, Leeds 2019. Self-indulgent twoddle, crap visuals and not much atmosphere. Left at the interval.
Big fan early on, saw them for the first time in ‘72 at Sheffield City Hall having won tickets in an NME competition; seen ‘em loads.
Would have walked out of Van Halen in Dallas in 2007, awful sound, but waited for ‘Jump’ 🙄