ROB, a couple of statements, then an opinion.
There are reliable poskim who are matir listening to music during the sefira.
There are reliable poskim who don’t.
(I don’t know how them came to their respective pesakim. Chumra/kula may have had nothing to do with it, this is just how they understand the bottom line.)
There is room to be meikil during aveilus.
Opinion: if I felt anything during the sefira close to the aveilus I felt for my mother, I would have beyond no issue with being meikil, if that is indeed appropriate. This does NOT mean I have to take on every chumra or hanhaga during the sefira to come to aveilus, just that when it comes to music, as this was the way I was raised and married into, I will continue NOT to listen to music, live or otherwise.