Plexamp is a Plex client app that provides direct playback for just about any music format you could dream of throwing at it.
This Plex companion can be used to remote control other Plex players and can be remote controlled itself.
You'll need a Plex Media Server to manage your music, next to this small client.
Besides support for standard media keys, it offers a global activation hotkey much like Spotlight on macOS (cmd+shift+space). This makes it quicker than ever to find something in your music library. There are a number of additional nice keybindings for power users.