Singing

[BlasterBates]

...and of course when you sing in your range it still "sounds" the same pitch as the original singer because singers with high voices sound lower than they are, there's more depth to the voice at their pitch. This is what I find. When I sing at the same high pitch as pop singers that sing high and a lot of them do, it sometimes sounds higher, because the tone isn't as rich, but when I drop it just a tone it sounds very similar. Sometimes though the key is a good key to play in. In fact Elvis's backing band retuned their instruments for some songs so that both the band and Elvis were playing and singing in their favourite key, Jailhouse rock for example, is in Db but the guitar is tuned down so Scotty Moore could play in E.
It's a tricky one when your perfect pitch for the song is something like Bb. Some songs we do live I accept the less than perfect choice for the pitch so that the guitar riffs are easy.

I was kind of trying to work King Creole in the setlist but A is a bit too low, and C is a bit too high but B and Bb really suck as keys to do guitar riffs and solos in, haven't figured this one out yet.

[NotAllThere]

There are exercises you can do to extend your vocal range, and to transition smoothly between the different voices. Warm up is essential.

For most people, practise is all that's required to maintain pitch. Mind you, when the stage foldback monitors go off, it can be a pig to stay in tune - you just can't hear the other instruments.

[BlasterBates]

My tip on a loud gig wear an ear plug or even two, you can hear yourself clearly then, otherwise with noise you can easily end up out of tune.