With one hand Apple giveth, and with the other it rips a long-standing feature away with no warning.
As part of the iOS 8.4 update that brought Apple Music, Home Sharing has been disabled for iOS devices. Home Sharing would let you stream your local iTunes library from your computer to your iDevice on the same network. It was a great way to press an old iPad into service by hooking it up to your speakers, and had been an iOS feature since v4.3.
Apple quietly updated its Home Sharing support page to reflect the change — which, by the way, doesn't affect Apple TVs. If you're willing to pony up a little cash, an Apple Music or iTunes Match subscription will probably fill the Home Sharing-shaped hole in your soul, albeit for $17.99 a month.