You could install a virtual sound device and make your music output to that sound device and also make your mic input from that sound device.
Well you simply do what I said above.I have voicemeter banana and a virtual audio cable, so I have all the software, it's just figuring a way to get it to work correctly.
Well you simply do what I said above.
Maybe best way would be dedicating a certain media player for this (maybe Windows Media Player? Because who uses that normally lmao).
(You'll probably need to restart the media player after changing this)
And then make your game capture mic audio from that sound device as well.