The most famous relatively-recent orchestral march may be the Imperial March from Star Wars (by John Williams). It’s not exactly 21st century, but it makes me suspect that maybe the movies are a good place to look for modern military marches.
Truly a great one, IMHO. Seriously - can’t you imagine standing on a balcony while your official orchestra belts this thing out and your tanks roll by below, en route to the conquest of Wales?
Is 1971 too long ago? Jerry Goldsmith’s theme from Patton is pretty damn memorable. And whistlable, too, if you agree that’s key to a fine military march.
If “modern” can stretch back to the 20th Century, the RAF March Past and US Air Force march would be modern, by definition. So would the Hymn to the Soviet Union, still being used for the Russian national anthem if memory serves.
And if “military” can be “that which has been performed/recorded by military bands”, you might consider the marches from the following films:
Things to Come
The Dam Busters
The Great Escape
Thunderbirds Are GO (watch the end credits for the actual British military band)
Ben-Hur (the Parade of the Charioteers)
Kinda like a high school band uses pop songs, Bos?
Robert Klein once did a skit on that talking about the song “Going Out Of My Head”, where he sang the song “march style”… Then he says, “They form a giant head, and they go out of it.”
Daughter also tried to convince the band teacher to do Those Magnificent Men in their Flying Machines. She thought she had a chance because he’s a trombonist who selects pieces that feature the trombone and, arranged right, this song’s a trombone showcase.
Can that arrangement be used for the euphonium as well or does it require the abilities of the trombone slide?
My brother plays the euphonium and DCI (in which any corps probably wouldn’t play Those Magnificent Men in their Flying Machines, but you never know) doesn’t use trombones.
Maybe not exactly what you’re looking for, since it’s usually music written in the style of a march, but not actually for a military purpose, but have you thought of checking out some twentieth-century classical composers?
The first thing that popped into my head was the march from Hindemith’s Symphonic Metamorphosis (the march begins at about 4:06).
Then of course you’ve got Charles Ives, who took traditional American marches and contorted them every way he could imagine. Often he aimed to intentionally recreate effects in his compositions that he would hear as accidental results of the circumstances of real performances, such as two marching bands playing different things as they pass by each other, or firemen banging a gong out of time with the music. Check out They Are There (on this recording the composer sings and plays piano, adding a slightly more twisted element than the more usual arrangement for orchestra and chorus possesses), Gong on the Hook and Ladder, and The Circus Band.
If I am right, the “Midway March” was something composed for the 1976 movie, and I have heard it once played by a real Navy band. I don’t know how often it’s included in the lineup, though.