Soft switch sound switcher using a few 2N3904 and resistors

Having two sound sources connected to the same output may be good for a while but sometimes you don't want to have both sources outputting sound at the same time and may want to switch between them. I wanted to be able to control this with a micro controller and not use a servo, so a mechanical switch is out of the question.

Transistor as switch

I know that you can use transistor as soft switches so I started researching how to build this.