HOWTO: Play random mp3s with mpg123
Assuming your mp3 collection is in $HOME/mp3s:
find $HOME/mp3s -name '*.mp3' | mpg123 -Z -@ -
The find command generates a list of .mp3 files in your $HOME/mp3s, and that mpg123 command says play songs randomly (-Z) from the list (-@) that I am feeding you via stdin. (-@ -)
To skip a song you are not enjoying, press control-C.
-d