Dancing and Musical Instruments: During this period it is forbidden to dance, play musical instruments or listen to them live or pre-recorded.
Vocals-only music: Even though such music has no musical instruments, if the music is of a joyous nature, it follows the same prohibition as listening to instrumental music. If the music however is of the type that awakens one to deveykus and is required by one specifically for this purpose, then it is permitted as long as it is listened to in private.
Recorded Cantorial music without musical instruments: Here to, if there is a specific need it is permitted as long as it is in private.
Recordings for Children: If the content contains both singing and music it is forbidden for children of chinuch age to listen. However, if the content is primarily stories etc. with some musical accompaniment, there is room to permit this. However, if the children are not of chinuch age, then it is permissible for them to listen to instrumental recordings.
Nursery schools for children at the age of chinuch: It is forbidden to play musical instruments to children of chinuch age even if there is a fixed schedule for doing so. One who’s livelihood depends on playing them musical instruments and stands to loose money from not doing so, should ask the opinion of a Posek.
Singing: With regards to joyous melodies, there are those that are stringent especially when there are a group of people together. In the context of a Seudas Mitzvah though, it is permissible to sing, however those present should be cognizant of not becoming exceedingly joyous.
The Poskim allow singing in all of the following cases:
1. On Shabbos.
2. While Learning.
3. When the melodies are of an awakening nature – whether alone or in a group of people who have joined together to strengthen themselves in Yiras Shamayim.
4. In order to keep one awake behind the wheel while driving.
Listening to music against one’s will: With regards to instrumental music that one happens to hear, be it on a bus, while on-hold on the phone or cell phone, is not prohibited on condition that one does not intend deriving enjoyment from the listening. With regards to one’s own cell phone, it is however correct to change the ringtone to a non-musical one.
Listening to Music while exercising: In this regard, one should consult with a Posek.
One does not make a Shehechiyanu during Bein Hametzarim. According to the essential law, though it is permissible on Shabbos. Yet according to the Arizal it is forbidden even on Shabbos.
One should not purchase a new item of clothing or a new fruit doing this period in order that one should not have to make a Shehechiyanu . If however such items will not be available after the three weeks or specifically in regards to a child’s desire for such an item, then it is permissible to allow the purchase and to make a Shehechiyanu. However, it would be preferable if possible to postpone eating the new fruit or wearing the new item of clothing until Shabbos.
A pregnant or sick individual who needs to wear or eat a new fruit, is permitted to do so but without making a Shehechiyanu .
Bris Milah, Pidyon Haben or seeing one’s daughter for the first time: It is permitted to say in all these cases to make a Shehechiyanu .
HaTov v’Hameitiv: With regards to an item that requires the blessing of HaTov v’Hameitiv i.e. there are those who are partnered in the joy, such as one’s wife or children, it is permissible to purchase the item as well as make the blessing.
C. Things that are permitted according to the essential law:
New Clothes and objects (Keilim) : There is no prohibition in purchasing items or new clothing that do not require a Shehechiyanu during this period, however there are those that hold neither to buy nor to wear such new clothing. There are those that are stringent only when it comes to purchasing very expensive items that bring one tremendous joy. And so, if there are items that one does not need specifically during this time, it is correct to be stringent and not purchase them until afterwards.
Dwellings: There is no prohibition in moving into a new apartment during this time whether rented or purchased. But there are those that are stringent to refrain from doing so for the sake of a “good omen” (“siman tov”).
Alterations and painting: There is no prohibition against alterations made to, or painting a dwelling during this time, however, the “Eliya Rabba” writes that is it is correct not to do so.
Outings (tiyulim): There is no prohibition during this time to go on outings, however one should be careful not to go to places of danger.
Washing: There is no prohibition to bathe during these days in the ocean etc. However due to the “fear of danger” during this ominous period, it is preferable to refrain from doing so unless there is a specific need.