sweet caroline

i was waiting for my egg sandwich to be cooked this morning at the place where i get breakfast.
sweet caroline was playing and i was working hard not to let loose and sing along.
then i noticed that the man to my right - a middle-aged guy - was singing along quietly.
this was pleasing enough.
better was when another man came along and stood to my left and also sang along under his breath.
it was a moment that almost made that moment in musicals in which characters suddenly burst into song seem plausible.