Media players can be complicated these days. Many, understandably, offer support for various streaming services or syncing of various devices. There are, however, a handful of players that still emphasize simplicity, flexibility and stability. With an open source development model and a text-based interface, cmus is a prime example of these back-to-basics media players.
In my early days of Raspberry Pi (RPi) ownership, I decided (as an exercise) to set up a budget remote-control music player in the other room. This involved: a pair of old computer speakers, an extra long stereo cable, the networked RPi, a GNU Screen session with cmus running, and an SSH client (e.g., VX ConnectBot) on my phone. Not the most efficient setup, but it worked!