Free audio mixer(router?) software for Windows

Question

With all this Covid-19 business comes remote schooling and my daughter has mandatory piano lessons. So far they've been making do with cell phones and Whatsapp video calls, but I feel like there are better technical options.

Here's what I have:

• A PC with Windows 10 (and obviously a sound card)
• A decent webcam with its own microphone
• Headphones
• A digital piano that can be hooked up to the PC via microphone or line-in.

Now all I need to figure out is how to route the sounds...

• The piano will be silent and only send sounds to the computer
• The headphones should hear the piano and the person on the other end of the video call (probably still whatsapp, but on PC), but NOT the webcam microphone
• The person on the other end of the call should hear the piano and the webcam microphone, but NOT their own voice.

In theory this is technically possible and should result in vastly improved sound on both ends, but I'm pretty sure that it can't be done with the default capabilities that Windows offers.

Does anyone know a (preferably free) program that could do this? I'm imagining something like the mixing panel of a DJ with multiple inputs and outputs that can be routed and mixed any which way.

Answer 1

OK, since nobody can answer me, I'll answer my own question. From this Reddit thread I found the "Voicemeeter Banana" software, which is free and does EXACTLY what I wanted plus much, much more. You can even route sound over network to other PCs and mobile devices! And it's totally free. (They do offer some more advanced software as Donationware, but Banana is free).

P.S. They still opted to just use Whatsapp, because it's simpler. Oh, well...