Sure. The controller, wherever you have it installed (PC/tablet/phone) is merely a remote control to the software running on the Sonos system. The speaker then executes the command to ‘get’ and play the music. Essentially, each speaker has a small computer and network device in it. 

There are some rare exceptions to this (AirPlay from an iOS device and ‘from this device’ on Android), but if it’s an online music stream, the speaker is getting it from the internet. 

So, is it possible to tell the speaker to play music, like a specific artist, album, playlist or station for 2 hours and turnoff?  

Sure. I tell one of my speakers to play a ‘station’ from the Calm stream, and then set a playback timer for an hour or two, and at the end it stops the stream. Sonos speakers don’t ‘turn off’, they just stop playing and after a short period of time, go into low power mode, waiting for a wake up message from the network (controller). 

Thanks. That’s something I wanted, too. 

I’ve just unsubscribed from google play / YT music as i cant cast off my phone to any of my 10 Sonos devices, and the Sonos app is just to limiting and YT Music itself is terrible feature wise.
Our whole use case at home is anyone can cast from their personal device to a Sonos in any room and have THEIR music playing without messing up another persons music account. and trying to avoid teh Sonos app as its limiting and feature poor next to the music app on the phones.

any suggestions on a music service other that Spotify that can still cast to a Sonos, and not have to use the Sonos app to trigger limited music functions?

otherwise i just have a really expensive internet radio station player