There is an intriguing custom among certain communities in Jerusalem of only hiring a one-man-band to perform at weddings. Sometimes this one-man-band individual even does the singing as well. Although most of the more familiar customs and restrictions intended to recall the destruction of Jerusalem have been in place for many centuries, the custom of restricting the size of a band at a wedding taking place in Jerusalem is actually only of recent vintage. Furthermore, and contrary to popular misconception, this custom actually has little in common with the many other “zecher l'churban” customs which are intended to recall the destruction of Jerusalem. Rather, it was instituted about two hundred years ago by a council of Jerusalem rabbis led by Rabbi Meir Auerbach in response to a cholera epidemic that was devastating the city. It had been suggested that the cholera epidemic was a Divine punishment for widespread laxity towards the Kotel and not treating it with its due respect.
The custom of only hiring a one-man-band is not observed by most communities. In fact, Sefardic communities never accepted the custom of restricting music at a wedding. Even among those who would normally subscribe to the customs exclusive to Jerusalem, it is generally only observed when both the bride and the groom were born and raised in Jerusalem. Indeed, most "Minhag Yerushalayim" customs, practices which are unique or distinctly identified with Jerusalem, are generally only observed by those who were both born and raised in Jerusalem. Minhag Yerushalayim practices are normally not things which a person takes upon himself simply by having moved to Jerusalem.
Additional examples of Minhag Yerushalayim include the custom of not holding any weddings during the entire sefirat ha'omer period (with the exception of Lag Ba'omer), the custom of lighting the Chanuka candles before reciting havdalla on Motzai Shabbat, and the custom of reciting kiddush levana in the month of Av before Tisha B'av. Even the minimum amount of dough which must be prepared in order to require the separation of the “challa” is subject to a different quantity in Jerusalem. As mentioned, these and all other Minhag Yerushalayim customs are not observed by everyone. In fact, many communities have differing approaches to each of these issues, as well.
There are authorities who suggest that the custom of not having a full band at a wedding was instituted only for those areas of Jerusalem which were in existence when the decree was made. Other authorities are of the opinion that the decree was made only for the Old City of Jerusalem and certainly not for the many newer neighborhoods that have been built in modern times. As such, neighborhoods such as Har Nof and Talpiot, which were not in existence 200 years ago, would not be bound to the custom according to this view.
It is interesting to note that according to normative halacha it is actually essential that there be quality and lively music at a wedding, as can be seen by the following anecdote. There was once a situation in the 14th century when music was forbidden to be played at weddings due to a government decree. As a result of this, the rabbis ruled that all weddings must be moved and held in a location or even another city where music can be played.
It is worth noting that many of the zecher l'churban customs which are actually halachically binding, as discussed in the Shulchan Aruch, have fallen into disuse. This includes the requirement to leave an empty place setting at every meal, for women not to wear all of their best jewelry at once, and the custom to recite "al naharot bavel" before the birkat hamazon at every weekday meal. Unfortunately, many individuals are not careful with these practices and they are largely ignored. Although there may be some justification for this phenomenon, one should make an effort to observe the traditional zecher l'churban customs.
 Beit Chatanim p.160, Salmat Chaim 1:77, 4:34
 Otzar Minhagei Nisuin p.314
 Beit Chatanim p.160
 Be'er Heitev O.C. 338:3, Imrei David 162
 Kaf Hachaim O.C. 560:18
 Sha'arei Teshuva O.C. 560:1
 Shuva Yisrael 1:71