Intro : D-G-Bm-G
Verse:1
D                             G
Angels we have heard on high, Sweetly singing o'er the plains 
Bm                            G
And the mountains in reply, Echoing their joyous strains
D                             G
Shepherds, why this jubilee?, Why your joyous strains prolong? 
Bm                            G
What the gladsome tidings be, Which inspire your heavenly song?
Chorus:
D     A  Bm           G
Gloria   in excelsis Deo
D     A  Bm           G
Gloria   in excelsis Deo
Pre Verse: A-D-A-G
Verse: 2
D                         G
Come to Bethlehem and see Christ whose birth the angels sing 
https://www.coveralia.com/acordes/gloria-mercyme.php
Bm                         G
Come adore on bended knee, Christ the Lord, the newborn King
D                         G
See Him in a manger laid, Whom the choirs of angels praise
Bm                           G
Mary, Joseph, lend your aid, While our hearts in love we raise
Bridge:
Bm                  G                     D                     A
How could Heaven's heart not break On the day, the day that You came?
Bm                    G                D                      A              
Salvation's reason to celebrate On the day, the day that You came
Chorus:
D     A  Bm           G
Gloria   in excelsis Deo
D     A  Bm           G
Gloria   in excelsis Deo
Ending:
(D-A-Bm-Gx4)
Gloria,  gloria, gloria
Hallelujah, hallelujah, hallelujah