Doing it electronically, you only need a CMOS analog switch. However, your control circuitry shares the same GND and power of your analog section.
These devices will require +/-5v supply so they may cover your analog voltage range:
Example of generic analog switches: 74HC4052 < This 1 IC will give you Stereo, 4 inputs, 1 output. < 100 ohm on resistance
74HC4051 < This one IC will give you mono, 8 inputs, 1 output. (Just use 2 for stereo).
Example of high quality analog switches: MAX4675 < The on resistance of this switch is only 3 ohm on resistance. (Getting close to a relay)
For these, you don't need a negative supply with these, but, I would still protect my analog IOs and this will cost a whole lot more than 74HC405x analog switches since it is a single normally open switch. Your digital no longer is connected to your analog with these photo-mosfet switches.
Optocoupled AC/DC mosfet switches: TLP222A < 2 ohm on resistance.
TLP222A-2 < This has 2 switches of the TLP222 in 1 package.
You may engineer a double break and mute in the middle design topology here if you think a 1 nano amp leakage current will be too much cross-talk on disabled audio channels.