Q. Dear Rov Shlit'a. As we spoke already, we are planing to make a Sheva Brochos for a dear family member on the night of Asara Beteves. Since the Taanis begins in the morning. Is what we are doing correct?
A. On question 957 in regard to attending a wedding or a Sheva brochos with music on the night prior to the fast of Asara Beteves, we wrote:
"Bais Avi (3,2,6) writes that the minhag is not to make weddings on the night of the Tenth of Teves since in reality the Ta’anis has already began but the prohibition to eat is only from the morning.
Ratz Katzvi (16) maintains that on this taanis a baal nefesh should begin fasting from the night before. Weddings should therefore be avoided on that night.
However, other Poskim are more lenient (Even Pina O.H. 45, P’ri Hasade 1: 2, Yavia Omer 6: 7, Tzitz Eliezer 7: 49). Although Halichos Shlomo (2: 18: 5) rules that one should not have a wedding on the night prior to a day fast, with the exception of Taanis Esther, he permits in need on the night prior to Asara Beteves (ibid. n. 21).
Da’as Torah of the Maharsham (551: 2) advises that although the Chupa is permitted, one should abstain from dancing on Asara Beteves.
Horav Shlomo Miller’s Shlit’a opinion is that in principle and by the letter of the Halacha, it is permitted to have a wedding or Sheva Brachos with music on the prior night of the Ta’anis. However, when possible one should be stringent. (He pointed out to the Sdei Chemed – Ma’areches Choson Vekalo p. 21-22)”
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit'a