How to open a.dat file?

I need some help here. I do a newsletter for our school band and the director just sent me his article. The problem is he sent it as a .dat file and when I open it, it is just a bunch of jumbled letters and numbers.I have tried to text him to ask that he send it in a different format, but he takes his dear sweet time getting back to people and I would really like to get this done. Can I somehow open it with word? I have tried word pad and notepad, but that does not work. Thanks to anyone that can help.