This was sent over to me as a PDF from a friend of mine. 
I have no idea where it comes from, but we have had great fun learning to sing the parts:
Bass, Tenor, Alto, and Soprano. 
These are the chords that we played along to on the accordion whilst busking!
     Enjoy!

A5 (x022xx@1)Am (x02210@1)name="chord_022000@1">Em   Am (x02210@1)G (320003@1)C (x32010@1)  C (x32010@1)   G (320003@1) Am (x02210@1)EmGau-de-te (022000@1)  Gau-de-te   Chris-tus est natus

Am (x02210@1)name="chord_320003@1">G  Am (x02210@1)Em (022000@1)F (133211@1)G (320003@1)Dm (xx0231@1)Em (022000@1)name="chord_x022xx@1">A5
Ex Ma-ri-a   Vir-gi-ne Gau-de-te