Three friends and I had an unusual experience. It gave me an opportunity to appear musically more literate than I really am.
We were playing some jazz to entertain shoppers in Market Harborough and came to the end of Running Wild. We play it in Bb so we finished on the Bb chord.
But Dave our sousaphone player - as he often does - then jokily added his own private slow coda, in which he played a long Eb and then a D to finish.
A smart-looking gentleman passing in front of us immediately stopped and said: 'Ah! A plagal cadence! And I bet you don't even know what that is.'
'The chord on the subdominant followed by the chord on the tonic', I replied - to his obvious astonishment.
Well, it was just a fluke. Though I have only a basic knowledge of musical theory, being virtually self-taught, it happened that I had recently been reading about the Plagal Cadence and how it has often been used for the 'Amen' at the end of hymn tunes.
I suppose we could use the plagal cadence more often as a kind of fun coda.
And in fact moving from the chord on the fourth to the chord on the tonic occurs all over the place in our music, notably in the 12-bar blues (bars 6 to 7) and The Apple Tree Chord Progression.