About Ross Campbell's point, in order to zap the vocals, the recordings have to have originated in stereo, so the original recordings would not work, but you make an absolutely brilliant point--since the vocal is being popped out of the arrangement, it doesn't really matter whose recordings you use.

It would be more than perfect to do your little bit with an accordionist--Along with Lilli Marlene and Falling in Love Again, and You should do La Vie En Rose, and finish with Der Treue Hussar, which is to many, the most plaintive "lost soldier" ballad of all--don't do more than three or four songs--you will be a novelty act at a party, and a good 12 minutes will be memorable, whereas,no matter what anyone tells you, ten songs will be tedious.

If you really want to get out of it, point out that Marlene never would have performed for the Nazis--