Question
What is the Halacha about clapping on Shabbat. Does it matter if it is in shul or not?
Answer
It is forbidden to clap hands on Shabbat if not by a Shinui - on the back of ones hand.
The Shulchan Aruch Orach Chayim 339 and the R"ma both tended to be maykel, in order that the people who clapped would not be commiting a sin.
The reason for the Isur is so as to stop one from fixing a musical instrument on shabbat. Nowadays, when we do not know how to fix instruments there is more reason to be Matir.
Rabbi Ro'i Margalit
