How can I stop music on HomePod using voice commands?

I am thinking of getting a HomePod system for my house, but I have one big problem. I can't find how to tell Siri to stop playing the music I am listening to. I usually stream Pandora, or perhaps Sirius XM and I can get Siri to start playing either of those on my iPhone or iPad. No problem. But the only way to stop playing music I have found is to physically touch the buttons. Voice command does not work - at least not that I have found. I am wondering if it will work the same way on HomePod? I don't want to delete the app, and I don't merely want to pause the playback. I just want to stop playing music and exit the app so I can free up bandwidth or computing resources for other tasks.

I'll appreciate any help, especially as I continue to think about HomePod.

[Re-Titled by Moderator]