To hear "Oh! By Jingo", rent/borrow the Jeeves & Wooster episode "Trouble at Totleigh Towers" (from the fourth season of the Hugh Laurie/Stephen Fry BBC series). The episode begins with Hugh Laurie playing the beginning, to half-way through the first chorus, and ends with the major characters giving a spirited rendition ensemble.

In another episode (anyone know which?), Laurie plays the seldom-heard introduction to "Nagasaki".