Yeah they shouldnt be allowed to remove it then, its technically not the same song if its in a different key!
Sadly, that argument doesn't hold
It may technically be a different song, but copyright includes the exclusive right of the copyright holder to create "derivative works" too. Which includes adapting a novel to a stage play, transposing a song to a different key - and also (addressing the other common objection) writing tabs which aren't correct - as long as they're "similar enough". Then there's the gray, philosophical zone of determining how many notes (or intervals) to change before it's not derivative anymore.
Of course transposing a song a semitone up makes all the notes different, but saying it's a different song won't hold up in court
Under the current legislation, tabs as well as guitar lessons of copyrighted works
are illegal. Whether that's how it
should be - and whether it does the music industry any good to shut down tab sites and guitar lessons - is another matter.
Needless to say, I don't think it's how it should be, and I don't think it does the music industry - much less the actual artists - any good. I also think the idea of software patents is the worst thing to happen to progress in the past 30 years. Yet that's how things are.