Q. Dear Rabbi, I am an avela in the first year mourning for my father. I want to honor my father. Am I permitted to attend an Upsherin? I don't know if there will be music, meal gifts so I want always to do the right thing. Thank you so much for your help and kindness.
A. If you make certain that there is no music, Nitey Gavriel (Avelus 2 – 32,4) permits attendance to a Chalaka Seudah (meal) or Upsherin during the twelve months of Avelus.
He also permits it even during Shloishim where the tradition of taking the child first time to Cheider is done as part of the Chalaka.
Horav Shlomo Miller Shlit"a disagrees, and recommends not to be present at the Seudah at all, even after Shloishim. You may attend the ceremony.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit"a.