Tim - the reason you can't hear it when a band downtunes is because you're an old fogey with bad ears after all those shows in the 80s my friend. LOL. I don't know how to explain it, other than by just hearing it. I'm an...okay singer, and I can absolutely hear when things are either downtuned or in a different key. I just listen to where my voice goes, and I can tell based on the original album. I am sure some of the more polished singers and the great musicians on here can tell you more.
re: DLR and Ozzy come on folks. I'm not saying I dislike their vocal performances. Obviously, I love some Sabbath/Ozzy solo and I love early VH. But Ozzy and DLR aren't blowing anyone away with their range and vocal control. In their prime, they were average, at best. Doesn't meant they weren't great for their respective bands at the time. But if you put Dio next to Ozzy, and Sammy next to DLR, there's no way on God's green Earth you could convince ANYONE that Sammy and Dio don't blow those two away in all aspects of pure SINGING.
Anyway, again, much respect for Blaze. I have yet to see him live. I am hoping that at some point, he'll be able to play a few shows on the West Coast.