Did she really? I'm thinking back to the Radio Contest Outtakes found on From the Top, and it seems like Karen is talking from the control booth during that, and coaching whoever is playing the timpani. "Golden mystery group, you want it up there...Would you repeat that please, up again..."I need to correct my previous answer, as I randomly, and for whatever reason, got to thinking about this question again.
Karen did cover the timpani part during the Mark Rudolph radio contest bit in the oldies medley found on Side 2 of Now & Then. Sorry about that!