Play random audio files from command line. It is mplayer which will play music command line.

playing_random_audio_file.sh

#!/bin/bash


if [ "$1" = "" ]; then
	echo "no directory defined!"
	exit
fi

if [ "$2" = "" ]; then
	echo "no file extension defined!"
	exit
fi

while [ 1 ]
do 

FILE=$(cd ${1};  find * | grep ${2}$ | shuf -n 1)

path1="$1$FILE"


/usr/bin/mplayer "$path1"

done

if you don't this command installed in your system. then first install it. using this command.

 sudo apt-get install mplayer

see the manual or help using command.

man mplayer 

or

mplayer --help