The full name of the song is ‘Pack Up Your Troubles in your Old Kit-bag, and Smile, Smile, Smile,’ published in 1915, with words by George Powell and music by his brother Felix. It featured in the American show ‘Her Soldier Boy,’ which opened in December 1916. ‘Pack Up Your Troubles’ is a wonderfully cheerful piece of music and the temp that you cannot help but start tapping your feet to it … a truly successful marching song!