Is the guy clapping DURING the music? If not, why worry?

Yes, DURING the music, that's what it makes so annoying....it almost
seems like he did it on purpose to make sure the recording became a
disaster...or maybe he knew that it was a recording which a lot of
people were interested in and he wanted to become (in)famous...

I guess the best you can do is throw away the channel with the
clapping. Any stereo image you may have had will be destroyed by
whatever processing you use in attempting to diminish the clapping.
Settle for one good mono channel.