"Ignorance is bliss." For a long time, I didn't understand, or misunderstood, that expression. I thought it meant that it's easier to be happy if you're stupid. Or something like that. And I supposed that's a valid interpretation.
Relevance? Now that I think about it, it's not the fact that some live albums are overdubbed, edited, or otherwise "fixed". It's that I know about it. If no one ever told me that some of my favorite live albums had massive edits and overdubs, I'd be happy as hell. It's knowing that the lead vocals were overdubbed months later in the studio, or the guitar solo was actually edited from a different night, or anything like that, that's messes with my enjoyment of it.
And it can vary, too. I grew up blissfully ignorant regarding Kiss Alive! It seemed to me an incredible, perfectly-recorded live performance, and I suppose it helped that it was recorded in my home town, at the same hall where I once saw Rush. Somehow knowing that it was basically a studio creation doesn't hamper my enjoyment. It still sounds incredible, and when I listen to it, I'm 12 years old again listening to it in my buddy Jim's basement.
But it's basically the opposite with King Crimson's USA album. David Cross has two blistering, amazing violin solos on that album. The credits mention "remix assistance" by Eddie Jobson on those two tracks, but at the time I didn't know who Eddie Jobson was and didn't know what it meant. Turns out Eddie played those solos; Fripp added them later, in the studio. Now, when I listen to those same tracks, they sound exactly the same of course, but somehow knowing that those amazing solos were not actually played by the band I'm supposedly listening to kinda ruins it for me. Which is kinda dumb, I suppose. I loved them before, the only difference is that I know that that's not what was played that night.
Then you have outright Frankenstein works like Frank Zappa often did. Basic tracks recorded live, studio stuff added later, and I don't have a quote from him on the subject, but if I did, I'm sure it would be something like "If it sounds good, what the fuck difference does it make?" Heck, Frank took different parts from different songs, sometimes individual parts from different songs, and put them together to create entirely new compositions. My first Zappa album and still one of my faves, Sheik Yerbouti, is one of these. Mostly "studio-sounding", but with parts of songs that clearly were recorded live, and final track ends with Frank, obviously live, introducing the band, and you hear the audience, and the album ends feeling like a live album just ended. Maybe that works for me because Frank was very up-front about it. Every track has detailed liner notes, and has stuff like "Overdubs: Lots" and "Overdubs: None".
So... sometimes ignorance is indeed bliss I guess.