What are the offline music streaming services with automatic selection and download of songs?

Question

Audio

I want to listen to music on my phone (Android) offline, but at the same time I don’t want to waste time searching for music and downloading it.
I like something like Pandora or iTunes Radio.
I imagine it like this: my phone, being connected to wifi, automatically downloads new songs into memory. And then I take it and just listen to new music without an Internet connection, while I can put likes or dislikes to improve the music I select.