What to do with non-licence music playing in the background?

I filmed a wedding reception for my Nephew. Live Events isn't really my speciality, so there's a few concerns I have that I'm not sure of what to do. Most of it I plan on playing Royalty Free Music over the footage, but there's some areas where I want to hear everyone speak, and they have non licence music playing in the background (though mainly you're hearing the guests and hosts). Because of that, not quite sure what I should do in those areas, and what I can and can not get away with. I definitely can't remove it without removing the guests and speakers at the same time.

All I can suggest is don't put it on Youtube. Once upon a time, incidental music (in the background, not the main focus) was OK, but anymore I think you are pretty much in trouble. The only thing that could potentially save you is that the DJ should have paid several different royalties, and this may cover you. But I'm not a lawyer, would be best to check with someone that handles this as a specialty. A copyright attorney might be a good first step, and if they don't handle it, they can refer you to someone that can help you.

Let it ride.

Fair use.

I always leave such music in. It's really the heart and sole of event filmmaking.

YouTube always send a Copyright claim. If it's allowed, the Publishers gets the ad revenue, if it's not, I take the whole video down.

Either way, it's the client who matters. They always get to hear the real music from their event.