@Kit-Bishop you are right. I was just thinking about possibilities. I forgot by the time I posted that the poster had wanted MP3. Adafruit has some boards that could be wired up.

https://www.adafruit.com/products/2133 - OGG/Wave
https://www.adafruit.com/products/1381 - MP3/OGG/Wave

These boards use a trigger to play that could come from the GPIO of the Omega. Their tutorials will show how to connect it to an Arduino, but connections will be similar.