Three Weeks – Background Music
According to the custom not to listen to music in the Three Weeks, are you allowed to watch a documentary which has some music in the background?
The Aish Rabbi Replies
Yes, it would be fine. The main issue with music is that it can bring a person to excessive enjoyment, especially if it is a type of music which could lead to dancing. Here the music is not your direct intent. However, you should try not to focus on it. Of course, it would be problematic to watch a musical during the Three Weeks.
Note that this ruling applies to Sefirat HaOmer and to mourners as well.