So as it turns out, it can be done. One can now stream native apps’ audio (and video, where applicable) using AirPlay to one’s original flavoured (/old/vintage/first generation) AppleTV from one’s iPhone using a little hack brought to you by the loverly chaps over at RemoteHD.
You will need:
- An iPhone (doesn’t need to be jailbroken)
- An old-flavoured AppleTV (does need to be jailbroken)