Some questions in regards to Tisha Beav this year (on Shabbos).
Q. If the minhag of your shul is to dance during Kabbolas Shabbos, should you also do it this time? (in the past, we danced, but some claimed it is not correct).

A. Nitei Gavriel (Bein Hametzorim 47) quoting Chassidic sources, mentions that it is permitted since otherwise it would seem like Avelus Befarhasia or an open display of mourning. Horav Shlomo Miller’s Shlit’a opinion is that it may not be so since most congregations on Shabbos Chazon do change the tune of the haftoro, since it is part of the established service, it is permitted.
However, the Rov recommends that one should maintain the traditions of his community.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a.