Use in a loop?

[scratchermatch]

I have the following command:
for i in 500; do sox -t mp3 /home/pi/x2music/$(ls | shuf -n 1) -t wav - | sudo /home/pi/PiFmRds/src/pi_fm_rds -freq 87 -audio -; done
which selects a random file from my folder and plays it. The problem is, once a single song finishes, the loop stops. I can't do multiple songs without actually being there to run the code. Any idea how I could do this?