As many of you know I've been to a lot of concerts.  It's what we did back in the day.  I've seen most of the great Classic Rock bands... way too many to mention. There are a few that I didn't see that I could have.  Some I regret missing, some I don't.
   I could have seen Jethro Tull.  At the time I was luke warm to them and didn't go. I regret not seeing them now.  It would have been nice to cross such an iconic band off of my bucket list.  Joni Mitchell I could have seen but didn't.  I regret that now.  I could have seen Elton John with Billy Joel.  My wife went but I didn't.  I can't even tell you why I didn't go to that one. DUH! 
    My late wife Marie scored two Bon Jovi tickets.  She asked me if I wanted to go.  I said "I'd rather have root canal but if you can't find anyone else I'll go."  Fortunately our friend Hope was glad to go with her.  That's one show I don't regrret missing.  I'm not a fan. 
    Is there a band or performer that you could have seen but didn't?  Do you regret it now? 

Got two booked this year so far.

Battle beast in february and wasp in April.

Wasp have been going 40 years, always liked them, the crimson idol is my second favourite concept album.
Blackie still sounds good, so that's definitely a bucket list job.

Battle beast is unfinished business lol
2019 I had a massive hypo about halfway through their set.
No idea how I got home in one piece. I definitely should not have been driving.
Couldn't even walk straight.

I do regret never seeing thunder. No idea why, just never got round to it.

Also never saw iron maiden in the late 80s and Bruce's voice has pretty much gone now, genuinely would not want to see them any more.

Can't think of any missed opportunities.

Would have liked to see Garth brooks first time round. The new stuff doesn't seem much good.

But generally I pretty much saw the band's I wanted to see

I technically could have seen Nirvana, but I would have only been a few months old :D Animal Alpha I'm really sad I never got to see.