Um, did 's neighbor actually register here now? :p
In my opinion, both are somewhat right.
Music in the garden is okay when it happens here and there. When it's 30°C, the paddling pool is set up, and someone is visiting, you're sipping cocktails and having a good time, you can also put a Bluetooth speaker out and play some music. That can happen more often.
But anyone who plays music in the garden for hours every day out of routine is, in my opinion, not very neighborly.
Somehow, the much-cited common sense tells you that these are actions you only do with some consideration when it really fits.