Neighbours often have BBQs and music out in the afternoon and evening. We're not really bothered, it's not super loud or anything, and we have a good relationship.
Yesterday they had a little mini family party in their garden and we were also out in our garden; my partner was doing dinner in the kitchen and the patio door was open. At one point without thinking he started belting out one of the songs (totally out of tune) opera style^^, without realising thatthey could definitely hear him; they turned the music down halfway through his not-so-magnificent reindition of Heal the World. We don't know if they were fed up with his singing or became self-aware that we could hear the music?
Anyways, we hope it won't put them off forever, but would you feel awkward if your neighbours started singing to something you're playing?
Asking as I often also catch myself singing in supermarkets when something I like is playigno on the radio 