Raspberry Pi Music Server
I am currently using a mixture of audio hardware in my home, including Chromecast, Google Home, first generation Apple Airport Express, a desktop PC running Shairport4W, and Raspberry Pi Zero Ws running Volumio. Because this collection of hardware is spread across multiple vendors, I needed a solution that would talk to everything.
This is the job of Forked-Daapd, a project to turn a Raspberry Pi into a music server that can stream to many different receivers. The video tutorial explains how to install and configure the project, then how to integrate it into Home Assistant.