Quick and dirty, but something like the project attached. I had to remove the MP3's to upload it, put them in your files folder and change the filenames.
I see from your code that you simply put MP1.Play and MP2.Play together with no lines between.
I had tried that before with apparently no success.
However, I found that it DOES work. My MP3 files had sounds too similar for me to detect them both.
Thank you for bringing that to my attention!