Use a separate computer and sign in as a "DJ" to pipe music into the room by playing the DJ's avatar on a spotlight space.
Use the Sync'd TV option to broadcast a very long youtube video.
Many people have recommended the 3rd-party application VB Cable if you want to both talk and share audio: https://vb-audio.com/Cable/
Note that we do not provide support in regards to 3rd-party tools or applications.
Technical (Mac only)
- Download the system extension (do read the "Please Read" section): https://github.com/mattingalls/Soundflower/releases/tag/2.0b2
- Download the latest SoundFlowerBed (an app for the menu bar that allows you to quickly choose input/output redirect): https://github.com/mLupine/SoundflowerBed/releases
- To redirect output to Soundflower, open SoundFlowerBed, and under "Soundflower (2ch"), choose your output device. (For me it's just "Built-In Output.")
- To make your mic play from Soundflower (which is now taking your audio out as its input), just choose "Soundflower (2ch)"as the source in your mic setup on Gather.