Look a the back of the receiver and you will see audio inputs, which you can use for an input from musical devices that use standard RCA cables. It is a lot of overkill to buy a Video receiver just to play music from a source like a CD player. The primary purpose of this receiver is to handle video coupled with audio.

Check the HDMI connections to make sure they are all secure. ^That seems silly, but you'd be surprised how often those come loose and folks pull their hair out trying to figure out the problem. If they are secure, then make sure the input on your TV is correct. If that is correct, then you have some audio-only setting engaged on the receiver. Cycle through the topics on the main menu to find video options and the one you have inadvertently used.