I don't think this is right. You can have Airport Expresses all around the place and they will even compensate for lag to play the music in sync.
[doublepost=1459045704][/doublepost]Here's an app if you don't have a computer to run iTunes:
Multiroom Music/Radio Player by WHAALE for AirPlay(TM) speakers by Logit Ltd.
https://appsto.re/nz/w6gKN.i