Short answers, pulled from the story.
A march is a musical composition with a strong regular rhythm, originally written to coordinate the lockstep movement of soldiers. It is a type of martial music most frequently performed by a military band during parades, though composers have also incorporated marches into operas, symphonies, and sonatas.
The modern march tempo is typically around 120 beats per minute, a standard adopted by the Napoleonic army to move soldiers faster. Funeral marches conform to the older Roman standard of 60 beats per minute, while circus marches can reach between 140 and 200 beats per minute. British marches typically move at 116 beats per minute.
John Philip Sousa was an American composer who revolutionized the march during the late 19th and early 20th centuries, earning the title "The March King". His most famous works include "Semper Fidelis", "The Washington Post", "The Liberty Bell", and "The Stars and Stripes Forever". No other composer's band marches have matched his popularity.
The trio is the third strain in most traditional American marches, typically marked by a key change that adds a flat. In John Philip Sousa's marches, the trio is often subdued, with the rest of the band becoming subordinate to a featured solo instrument, as in the famous piccolo solo in "The Stars and Stripes Forever".
American marches use the French quick march tempo of approximately 120 beats per minute, adopted because U.S. military bands aligned with France and other continental European nations during early wars with Britain. British marches move at a slower 116 beats per minute. A military band playing at the traditional British tempo would seem unusually slow to American listeners.
The Defile March is one of the earliest and most enduring Japanese marches, composed in 1886 by Charles Leroux, a French Army officer serving as an advisor to the Imperial Japanese Army. Originally two separate marches based on Japanese melodies, Fusouka and Battotai, they were later combined into the march recognized today, which the Imperial Japanese Army adopted as their signature march.