I am in the Year avelus for my Father a”h. Can I attend a Chanuka party with food and aunts uncles cousins (some distant), but with no music?
There is room to be lenient in this matter.
It is preferable, if possible, that the party should be at home.
Iggros Moshe (Yoreh De’ah 3:181) writes that an avel should not attend a Chanukah party. However, other authorites permit attending a family gathering (without music), such as Rav Shlomo Zalman zt”l (Halichos Shlomo Vol. 2, Chap. 17, no. 3), and see also Beis Lechem Yehudah and Gilion Maharsha (Yoreh De’ah 391:2).
Note that a Chanukah party is not necessarily a se’udas mitzvah, and it is preferable that Divrei Torah should be spoken, which render it a se’udas mitzvah (see Orach Chaim 670:2).