Question / Help How to get two audio source

[ilwoody]

Hello guys. I hope this is the right place to post this question. Please do let me know where to move this topic if needed.
I'm giving online piano lessons and I'd like to accomplish this.

Normally my student is just able to either listen to my voice (from integrated mic) or internal audio (any audio played from youtube videos or whatever). Since I will link my piano keyboard via an external audio interface, I'd like the student to both listen to me and the sound from the keyboard. However, with standard video chat apps, it seems impossible to accomplish this because I'm allowed to just pick one source for audio in.
Is there any practile solution with obs?
Thank you for clarifying this to me

 

[koala]

Use an external mixing application like Voicemeeter: https://www.vb-audio.com/Voicemeeter/banana.htm
With this, you are able to mix your mic and your piano keyboard and output the mixed audio to a virtual mic device. This virtual mic device is what you feed into your chat app instead of your two separate devices.

With OBS, you don't need this, because OBS has an internal mixer that is able to mix an arbitrary number of audio sources into the streaming or recording audio output.