A WUC Xmas Quiz 2017 Questions

A list of chords of 20 choruses taken from WUC songbooks 1 to 6 are listed below. Formatting and duplicate chords which were next to each other have been removed. Can you identify the songs?:

1. [C] [Gdim] [G7] [C] [Gdim] [G7] [C] [E7] [A7] [D7] [G7] [C]
   
2. [F] [C] [G] [C] [F] [C] [G] [C]
   
3. [F] [C7] [F] [C7] [F] [C7] [F] [C7] [F] [C7] [F] [C7] [F] [C7] [F] [C7]
   
4. [C] [F] [C] [F] [C] [G] [C] [G] [C] [G] [C] [F] [C] [F] [C] [G] [C] [G] [C] [G]
   
5. [C] [Am] [F] [G7] [C] [Am] [F] [G7] [C] [Am] [F] [G7] [C] [G7]
   
6. [C] [G7] [C] [G7] [C] [G7] [C] [G7] [C] [G7] [Am] [F] [G7] [C] [G7] [C]
   
7. [G7] [C] [A7] [D7] [G7] [C] [G7] [C] [A7] [D7] [G7] [C]
   
8. [G] [C] [G] [Em] [G] [D7] [G]
   
9. [F] [C] [C7] [F] [F7] [Bb] [Gm] [F] [C] [F] [A7]
   
10. [C] [D] [Bm] [C] [D] [Em] [C] [G] [C] [G] [Em] [A7] [D7]
    
11. [A] [F#m] [Bm] [E7] [A] [F#m] [Bm] [E7] [A] [F#m] [Bm] [E7] [A] [Ab] [G7]
    
12. [F] [D7] [G7] [C7] [F] [D7] [G7] [C7] [F] [D7] [G7] [C7] [F] [D7] [G7] [C7] [F] [D7] [G7] [C7] [F] [D7] [G7] [C7] [F] [D7] [G7] [C7] [F] [Bb] [F]
    
13. [C] [G] [G7] [C] [C7] [F] [G] [G7] [C]
    
14. [A] [D] [A] [E7] [A] [D] [C] [A] [D] [C] [A] [D] [C] [A] [D] [C]
    
15. [G7] [C] [G7] [C] [F] [C] [G7] [C]
    
16. [C5] [F/C] [C5] [G] [C5] [F/C] [C5] [G] [C5] [F/C] [C5] [F/C] [G] [C5] [F/C] [C5] [G] [C5]
    
17. [G] [D] [Em] [C] [G] [D7] [C] [G]
    
18. [C] [Am] [F] [G]
    
19. [D7] [G] [C] [G] [C] [D7] [G]
    
20. [G] [Am] [C] [G] [Am] [C] [G]
    

...answers will be linked here some time on Boxing Day evening! - good luck