Shorthand: I go to youtube and pick something thematically appropriate that has a 3+hr runtime.

Some notes from the front:
Don't play music in the middle of the table, or from the same direction the DM is speaking. It will just interfere with people talking. If you've got speakers scattered around your house or you have a single device you can play from, place it off to the side. Most homes will echo the sound somewhat to give it a more "it's in the background". You want people to feel like they're IN the situation, not in front of a movie screen.

Make sure the volume is kept low, no matter how much you love this song or how appropriate it is. It's BGM. This is a mistake even big-screen features make.

Don't undervalue SILENCE. The moments when there is NO sound can be far more impactful than the moments where there is.

Respect when a player asks you to pause the music or turn it off because they can't hear or they've got a headache. Valuing the well-being of your players goes a lot further than the right music choices.