If you can't hear a few seconds of a song and know what key it was played in you shouldn't attempt to apply an offset to a source.
I don't have perfect pitch, but I can adjust a recording so it's in the same key, and in tune with another recording, for example the studio version of the song!?
I must listen to both and switch back and forth to achieve this, but it's not overly difficult if you've ever tuned a guitar or a wind instrument. But yeah, without ANY musical training, I'm not sure it would be so simple.
But yeah, fixing warble is not something I've ever dealt with, though I guess it might make some of my old cassettes into potential matrix material, if the speed could just hold still!!?? Capstan, eh? I'll look that up.http://www.celemony.com/en/capstan
This is exciting! Capstan is pretty cool! $$$