If you could bring back one great artist that has

I'd like to see Bach back as a keyboardist/composer prog rocker. Like Tony Banks in Genesis or Rick Wakeman in Yes. Maybe collaborate with Steven Wilson. That would be awesome.

..or Mike Pinder in The Moody Blues. Bach + mellotron = unheard of level of awesomeness. Ralph Karsten owns and plays Mellotron. Another good pairing!

..or I saw Devo live recently and was honestly thinking that Bach could have played really well into that, if not below his level of artistry.

..or for a bigger paycheck these days, Bach might fit nicely into Muse or Radiohead. Imagine the possibilities!!!!

Yep, bringing back Bach would seem to open up the most interesting avenues of anyone mentioned. Duke Ellington in his prime would still be right up there as well in terms of modern day versatility. Beethoven I can see possibilities for him as well. :^}