Uncle Bert refers to a 'merry tune' in his diary that was sung by his company on their marches... It lead to me trying to find out where it was from and discovering:
That ever was Tragedized
Company of Tragedians'
written by Henry Carey (1687-1743)
This wiki explains it was a satirical play written in 1734 and Henry Carey's works were the sort that later led to tongue twisters!!!
If you are so inclined to actually read this nonsensical play you can do so at the Chrononhotonthologos website