Was very interested to hear about the possible Jethro Tull quad thing. 79 sounds pretty late in the game though, so would be surprised if it actually turned out to be.
All the mentions of quad simulcasts of "ABC Wide World In Concert" are definitely a big question mark. The CalJam simulcast is the most commonly referenced one. I actually was able to track down one of the mix engineers for the CalJam stuff, and he said that no quad mixes were done (at least by him). I found a rip of the ELP boot a while back, and while it is very good quality, doesn't seem to show any signs of encoding. Some of the applause shows really strange phase info on them, but it turns out a lot of the applause in the broadcast was "flown in" during the mix down. I have a VHS boot of ELP at CalJam that claims it is being broadcast in quad on something like KLOS, but at best, maybe they were upmixing it.
All the mentions of quad simulcasts of "ABC Wide World In Concert" are definitely a big question mark. The CalJam simulcast is the most commonly referenced one. I actually was able to track down one of the mix engineers for the CalJam stuff, and he said that no quad mixes were done (at least by him). I found a rip of the ELP boot a while back, and while it is very good quality, doesn't seem to show any signs of encoding. Some of the applause shows really strange phase info on them, but it turns out a lot of the applause in the broadcast was "flown in" during the mix down. I have a VHS boot of ELP at CalJam that claims it is being broadcast in quad on something like KLOS, but at best, maybe they were upmixing it.