Thank you for the quick reply! AirPlay works fine, I've used the Apple TV device to watch movies and play music television for years without issue.
I'm trying to use it in a new way, specifically to play music without having my television on (because I don't need to see the menu when I'm using AirPlay on my iPhone or iPad). To accomplish this, I connected the Apple TV to the Yamaha HTR 5930 receiver via Digital Optical Audio Toslink cable. I changed the input setting on the receiver to "DTV/CBL" to match the optical input label on the back of the receiver. No sound comes out.
I already referred to the Apple TV (2nd and 3rd generation): Troubleshooting audio issues article, but that did not resolve the issue. Any ideas for additional troubleshooting?