Command line: mpc
mpc is a command line client for the Music Player Daemon (MPD). Pretty nifty for controlling it in the command line and a bit of automation.
Subcommands
The subcommands mainly deals with interacting with the server, letting you play and manage your music in the command line!
listall
lists all of the recognized files from the music directory.play
play the playlist from the server.add [FILES...]
add the files (that are in the music directory) to the playlist.
Examples
Welp, it's a music daemon client so it should be simple enough.
Randomized playlist
Even more useful if you schedule it.
mpc listall | shuf --head-count 10 | xargs --replace='{}' mpc add '{}'