Try making a .wav file perhaps it cant play .mp3. At least test with .wav file. I am fairly sure you would need a MP3 player program for that to work something like WinAmp supports command line I believe.
EDIT: Yes WinAmp supports command line:
1. Using the command line interface to control Winamp
Note: New 5.11+ multi user/instance commandline switches can be found below.
The simplest, easiest, least powerful way of controlling Winamp is to
execute winamp.exe yourself. By simply calling winamp.exe with various
command line options, you do a number of things. For example:
C:\path\to\winamp\winamp.exe /ADD C:\mp3\whatever.mp3
(Adds C:\mp3\whatever.mp3 to the playlist of a running Winamp, if Winamp
is running, otherwise it opens Winamp and plays it outright)
(Creates a new instance of Winamp, even if Winamp is already running)
(Plays the file C:\mp3\file.mp3, regardless of whether or not Winamp is open)
(Opens Winamp with a different Window Class name "myclassname")
As you might notice, what you can actually do using the command line
interface is pretty limited. It is really easy to get started with,
though. You can also specify multiple files and or directories on the
command line, such as:
C:\path\to\winamp\winamp.exe /NEW "C:\my mp3s\" "C:\bigplaylist.pls" "C:\download\new song.mp3"
For more advanced Command Line switches you can use a plugin such as WACommand.