Hello! I’m a bit confused by the ability to "choose" which period of the Omer a person will keep (starting the 15th of Nissan vs. 2nd of Iyar). I understand that minhagim differ amongst communities, but the fact that an individual can change his own custom from year to year is puzzling and unlike anything else i’ve heard of...especially since we are trying to commemorate a specific mourning period in history. This is further complicated when considering simchas, such as weddings. I recently attending a wedding which took place before the 2nd of Iyar, and of course, had music and dancing. Since I am keeping the first period of the Omer, I wasn’t sure if I was even allowed to attend. I have to assume that there were others at the wedding who were also holding according to the first days. Is it just a matter of stringency, or do simchas actually override the mourning customs? Thanks!

Shalom, Thank you for your question. The ruling you are referring to (the ability to "choose" which period of the Omer a person will keep as a semi-mourning period), is based on the response of Rav Moshe Feinstein zt"l. In general a person is obligated to follow the customs of their community. Here, however, Rav Feinstein zt"l writes (Orach Haim, 1, 159) that really the essence of the custom is to have a semi-mourning period of thirty-three days, and the different practices of which 33 days to designate as semi-mourning days are just different applications of the one custom. Therefore, it makes no real difference which 33 days are chosen, and as long as one is not going to cause arguments by changing local custom (such as in most places today where one can find people who choose many different 33 day periods, and there is no one set local practice), one may change their particular practice each year. This is not similar to other cases of changing one's customs, as here the same custom is being upheld – that is to have semi-mourning for 33 days. In relation to attending a wedding during the days that you personally are accustomed to refrain from music in, whilst the bride and groom follow a different 33 day period – the poskim rule that you may attend and also dance, so as to take part in the mitzvah of adding joy to the wedding celebrations. Blessings.