A close friend of mine observes the latter mourning period of Sefira, beginning after Rosh Chodesh. I observe the earlier period, ending with Lag Ba’omer. My friend is getting married before Rosh Chodesh. May I attend the wedding? Thank you!
Yes you may attend. R’ Moshe Feinstein explains that the reason is because the wedding permits music not only for the chosson and kallah, but for all those that attend the wedding.
Igros Moshe O:CH 2-95, Kovetz Halachos (Sefiras Haomer) 9-6.