americanaudiophile :
Look into Sonos. Not the cheapest but very easy to set up, Works great with well developed software, good tech support and can be done in stages. They have stand along speakers, a soundbar, or boxes that will connect to existing systems or passive speakers. Very reliable and supports all the streaming service. Free app for control.
+1 on Sonos.
In my home I have 16 in ceiling Polk speakers (18 speakers total if you include my surround center and sub) which are run by a 12 channel Episode amp and 3 Sonos connect boxes.
The Sonos connect boxes (~$349 ea) can be synchronized to all play the same thing or different things. They output to different combinations of channels on the amp which triggers on and off depending on sound. One of the boxes also outputs to my surround sound which is the last 4 speakers + center and sub, so that I need to manually turn on and set the volume to match the other speakers. Now this setup was a bit expensive and required wiring the speakers up before the house was complete.
Sonos also offers powered speakers or even connect boxes with amps to run your own speakers. So you could put powered speakers throughout the house and sync or run them independently (the Sonos app makes this easy with grouping). You could also use 1 connect or connect amp box as your "input" basically it has an RCA, coax digital, as well as optical input which you can plug in a CD player, tv, whatever and use that as an additional source (aside from the built in apps which is like Pandora, XM, Spotify, Amazon, and can play music stored on your phone or on a computer set up as a media server in your home).
It all depends how much you want to spend and how open your house is.