Audacity, although a nice enough free cross-platform audio editor, is child’s play compared to what is out there for the pros. I am a musician with a just enough experience to be dangerous, and it is almost scary how powerful some of the professional software is. Think of what you have seen photoshopped and apply it to audio only.
I have gone into a studio, sung and/or played a few takes I wouldnt have wasted a cassette tape on in the past, and seen the studio gurus turn it into something fairly listenable.
Mr G is one of those studio gurus....and you have no idea what he can do with the toys he has. Just last week he manufactured a word for a jazz song he was mixing. The singer left the word out all together, and he has it being sung on the final product. Even he, as an old pro, was impressed.
There is software that will allow you to tune, edit, (time or words) or even replace one voice with another. I know one producer who sings a part, then replaces his voice with that of the “singer” (who isn’t too good). That way the song is in tune, in rhythm, and with “heart”. Its the only way they got the album done. (and no, I will not tell you who it is)
With the amount of material out there with Mel’s voice on it, this tape could be made up out of whole cloth if someone wanted to.
“...is childs play compared to what is out there for the pros...”
I was aware of that. It wasn’t all that difficult (if you had the right equipment & experience) back when recording was all-analog. Since we’ve gone digital, there has been NO LIMIT to what could be done with enough computer power, time, and intent.
Back in 1985, I looked at a sampling digital synthesizer at Radio Shack. It could record any instrument, and transform it into nearly any other instrument. For the few things you couldn’t fake, you could buy samples. It is probably child’s play to do things like that, now. I’m just tone-deaf enough that there is not any point in my trying to play with that stuff, now. On the other hand, I’ve got a perfectly good ocilloscope, which would probably let me do it anyway. If there is a will, there is a way.