There are a variety of products like Google, Bose QC II Bluetooth headphones, Home and Chromecast that extent the functionality even further. There is also a second Google Assistant app for those who want a quick launch icon on the home screen. The hardware stuff costs money, but Google Assistant is free. Amazon Alexa is another excellent app in this space, but it doesn't support Google Android quite as much as we would like, yet. We don't typically recommend streaming services to people. Everyone has their preferences and saying that one is better than another is a matter of opinion at this point. Except for Google Play Music.
The app can read both your local files and the music you like online. Additionally, you can upload tens of thousands of songs to the service for free. YouTube is kind of a given. There's more content there than a human person can watch in several lifetimes. That includes music videos, educational videos, news videos, reviews, video game let's plays, and a whole lot more. YouTube Music is also now a thing. However, it's not quite as good as Google Play Music yet.