There are actually 2 verses to GSTQ, However only the first verse is normally used.
In fact there are three verses to the official anthem.
Several others have also been added at various times, the longest lasting being an anti scottish one from 1745 praising general Wade.
Various others such as this:
From France and Pretender
Great Britain defend her,
Foes let them fall;
From foreign slavery,
Priests and their knavery,
And Popish Reverie,
God save us all.
have been tacked on along the way and just as quickly dropped.
The one sung on Saturday as has been pointed out was very weird and no shame on Tompkins for stepping out.