Shulchan Aruch Orach Chaim 551:17 says:
טוב ליזהר מלומר שהחיינו בין המצרים על פרי או על מלבוש אבל על פדיון הבן אומר ולא יחמיץ המצוה
It is good to avoid saying Shehechianu in the three weeks on a fruit or clothing, but on a Pidyon HaBen he says it and doesn't postpone the Mitzvah.
The Magein Avraham (s.v. ולא יחמץ המצוה) quotes the Maharil as saying ...
Rav Moshe Feinstein (Igrot Moshe OC 1:168) holds that in general one can have a wedding on the night of 17 Tammuz when necessary, but says in that same teshuva that for sure when the fast is Nidche that you can't have a wedding Saturday night. (I assume all other restrictions follow.)
In all likelihood this is not allowed.
See shulchan aruch siman 551 siff 7. The Shulchan Aruch mentions an that one is not allowed to be misaken ( you'll soon see why I'm not translating this) new clothes or shoes from rosh chodesh Av.
The Ramma adds that we allow non Jewish workers to be misaken the items during the nine days so that they will be ready ...
When I was a student at Yeshivat Har Etzion, R' Binyamin Tabory gave a Shi'ur on Ma'aseh Rav, based on the Rav's teachings and Minhagim. When he discussed Sefirah, the Three Weeks, etc., he said that if, hypothetically, one could go to a movie at all (which he did not feel was so simple, for reasons relating to issues of modesty - he said he once went to a ...
R' Shlomo Aviner takes a strict approach and writes unequivocally that the answer is no (#17 from the top).
סטנדאפ בבין המצרים
ש: מותר ללכת למופע סטנדאפ?
Standup during the 3 weeks: Q: Is one allowed to go to a standup show?
ת: ודאי אסור. אסור כל השנה בגלל מושב ליצים. ע"ז יח ב. קל וחומר בין המצרים
A: Definitely forbidden. [Going ...
Yes, based on The Ari Zal and The RaShaSh you say both tikunnim except on Rosh Chodesh where you recite only Tikkun Leah and Shabbat where you say neither. On Tisha b'Av itself at Chatzos HaLayla we only say Tikkun Rachel.
This is how almost everyone (if not everyone) who merits to say Tikkun Chatzos is noheg.
.כל המתאבל על ירושלים, זוכה ורואה בשמחתה
In addition to the other excellent answers, I want to point out one more source because of its direct relevance to the specific question asked.
The Talmud records (Megillah 5b) that Rabbi Yehuda HaNasi publicly bathed in the city of Tzippori on the 17th of Tammuz. Tosfot and Rashba there already point out that he was making a public statement that the ...
Nitei Gavriel Bain HaMatzarim page 101 says that one may get engaged during the period of 17 Tamuz - 29 Tamuz, however no music or dancing is allowed.
Page 102 says that according to Ashkenazik custom we do not get married the entire 3 weeks, however Sefardic custom is to allow weddings during the period of 17 Tamuz - 29 Tamuz.
Page 105 says that one is ...
All surgery that can safely be postponed until after Tisha B'Av should be postponed. See R. Simcha Bunim Cohen's Halachos for Daily Living, volume on the Three Weeks and Fast Days. Published by ArtScroll.
Nitei Gavriel Aveilus2 3:1 says that the prohibition of cutting hair beyond 30 days is only for a parent, which requires one to be told that he looks unkempt prior to taking a haircut. For one who is mourning a child or sibling the prohibition is only for 30 days and then may cut his hair immediately after the 30 days whenever he wants because the Aveilus ...
Based on (O.C. 554:21) אֵין שְׁאֵלַת שָׁלוֹם לַחֲבֵרוֹ בְּתִשְׁעָה בְּאָב, וְהֶדְיוֹטוֹת שֶׁאֵינָם יוֹדְעִים וְנוֹתְנִים שָׁלוֹם, מְשִׁיבִים לָהֶם בְּשָׂפָה רָפָה וּבְכֹבֶד רֹאשׁ,
Rav Ari Enkin concludes his article saying,
While it may just be that those who choose to be strict and not offer
any greeting whatsoever when in mourning or on Tisha B'av ...
Shulchan Arukh, Orach Chayyim 551:6:
כלים חדשים בין לבנים בין צבועים בין של צמר בין של פשתן אסור ללבוש בשבת
ואנו מחמירין מראש חודש ואילך):
New clothes, whether they are white or colored, whether made from wool or flax are forbidden to be worn on this Shabbat (and we are stringent not to do so from Rosh Hodesh Av onwards.)
See Magen Avraham who ...
For Ashkenazim, it seems that an individual cannot buy furniture during the Three Weeks but a couple or a family can:
Sefardim disagree and do not allow it:
The Three Weeks are those days between 17 Tamuz, when the walls around Yerushalaim were breached by Titus's army, and 9 Av, when the Bais Hamikdash was actually destroyed. It would have been a period of heavy fighting, more than just a siege.
As to your second question: The Gemara (Tanis) doesn't mention a mourning period starting from 17 Tamuz. It's an ...
Rav Gormon of Chabad Toronto: recommended to me that until the Hodesh She'hal Bo (ashkenazim) or Shavua She'hal Bo (sepharadim) it is permissible, min ha'din. From that point onward, it would be recommended otherwise, from the mishna's point of משנכנס אב ממעטים בשמחה.
I found this:
The sources seem to be Mishna Brura: תקנא/טז and Magen Avrohom תקנא\י
Kitzur Shulhan Aruch says that it is permissible for someone whose profession is musical instruments to play in a Goy's house, that implies I guess that it's prohibited otherwise.
You're right, it's a ...
Generally, if the music is not for one's specific enjoyment, you can listen to the music. In your scenario, you are not the one listening to the music, anyway - your child is. And, s/he is not even listening for the enjoyment of the music, itself, anyway. Plus, there may even be more leniencies for a child below bar / bat Mitzvah, anyway.
In summary, I ...
There was a big fight over this in Israel, I believe during the 70's / 80's. The chief rabbinate was dominated by Ashkenazim and they forbade weddings during the three weeks. One of the many things Rav. Ovadia Yosef is known for was his fight for Sephardi traditions, one of which is that weddings are allowed during the three weeks:
Rabbi Ovadia Yosef ZT”L ...
JewishMusic.FM has a whole list of [Jewish] acappella music.
My personal recommendations from there include the Maccabeats and Lev Tahor. I'm familiar with AKA Pella, Six13, Beatachon, and the Chevra's acappella album -- some is good, some not. But hopefully there's enough in this list to last through sefira for you.
The poskim today differentiate between digitally modified a capella music vs. straight voices:
Rav Belsky is quoted as saying,
There are basically three types of a cappella.
One is where the musical sounds originate from human voices but the
natural properties are digitally modified with computer software to
attain quality of sounds that are ...