Shairport Sync is an AirPlay audio player - it plays audio streamed from iTunes, iOS devices and other AirPlay sources such as Quicktime Player and ForkedDaapd, among others. Audio played by a Shairport Sync-powered device stays synchronised with the source and hence with similar devices playing the same source. In this way, synchronised multi-room audio is possible without difficulty. WWW: https://github.com/mikebrady/shairport-sync