Q. See question above. If someone is celebrating the Bar Mitzva as mentioned by keeping during that year the later period of mourning, can the guest that keep the first Minhag also dance to the sound of the music?
A. Horav Shlomo Miller’s Shlit’a opinion is that it is similar to a wedding and the guest can indeed partake in the dancing and music of the Simcha.
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit’a