The Rav compares the 3 weeks to the twelve months of mourning, and following that comparison he permits shaving during the 3 weeks (but not the 9 days) but forbids large social gatherings.
What does he say (or what is said in his name) about listening to recorded music during the 3 weeks? What about going to see a movie in theaters?
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 movie with his sister and a friend in the 1960s that was supposed to be totally "fine", but the previews were inappropriate), the Rav did not feel that the experience of staring blankly at a screen in a dark theater, in which if anyone spoke to you you'd be upset, fit the definition of public Simḥah that was banned during the 12 month mourning period and, by extension, the Three Weeks and Sefirah.
If I recall correctly, he also did not seem to see any inherent problem with recorded music, though I'm not sure that either R' Tabory or the Rav would allow someone to listen to recorded music if the person were doing so specifically to lift their spirits or anything similar. I think the point was that recorded music playing on the radio while you're driving or at work isn't a problem. (That's just my take, not anything he said specifically.)
R. Aaron Rakeffet spoke about this in a lecture:
During the Three Weeks, so someone asked the Rav, he said: "Rebbe, I'm used to having classical music on in my car; it helps me drive better, I can concentrate more on driving." So the Rav was matir. The Rav said the issur of music, not hearing music, is when you hear it as a group, when you're rejoicing, when you're happy. But if you're hearing it to relax your nerves when you're driving, this is what I was told the Rav was matir.
