Yes I know what you mean with the LED lighting; also what I find even worse is the use of smoke machines. At the bigger festivals / gigs its the first 3 songs of any act & no flash so you have to be very quick.
What I do now is take individual photos of the main members of the band/group waiting for the lights to change until something comes up that’s usable. Failing that, then its convert everything to black & white & you then you might have something that’s hopefully usable. I also switch to spot metering a lot of the time.
With your first 2 photo’s I personally would just crop them for the singer, the bass player has a microphone in front of him (totally unusable in IMHO) & like you have said the drummer & the piano player the highlights are blown.
For me personally the noise/grain in rock group photos does not bother me in the slightest in fact I think it can add to the atmosphere of the photo. (But that’s just my opinion). I quite happily shoot at anywhere between 4000- 16,000 ISO.
Hope that’s of some help but I suspect other photographers do things totally different to what I do.
These might give you some idea of what I’m trying to say believe me the lighting & the smoke was really bad when this group were on stage.https://www.facebook.com/media/set/?set=a.387308171337543.87339.149059145162448&type=1
The lighting was even worse when Gary Numan was on stage, very very dark & more smoke than bonfire night. The two red photos I included just to show how difficult things can get. So it’s just a matter of waiting for the lights to hopefully become useable.https://www.facebook.com/media/set/?set=a.387306571337703.87337.149059145162448&type=1