I learned to march in basic in '96, I promise you it stays w you.

Yeah, I did basic training decades ago, and could probably do it right with maybe an hour-long refresher course. Even without that I'd probably be be fine just marching, it's more the "eyes left", "present arms", handling turns, etc. that would need work.

That said, you tend to follow someone's lead. From what I remember, they declare it like "by the left, quick march" and that means you're marching at a standard "quick" pace and you're lining up with whoever's to your left, and the left column follows the person in front of them, so basically led by whoever's in the front-left position of the formation. That means if people to your left, or people on the left-most column are out of step, it will have a cascading effect through the ranks.

But yeah, it's pretty standard to call out the march, and they'd definitely do that if they cared.

What's also funny is that at one point as the soldiers were marching past, they were playing "Fortunate Son" on the PA system. Now, that's massively ironic given that the song is basically about Vietnam-era draft dodgers who used their family's wealth to get out of Vietnam service like Trump.

But, making it worse is that the song has a slightly faster pace than your typical rock song at 135ish BPM. The US military generally marches at 120 BPM. It's actually really hard to hear a song at 135 BPM and march at 120 BPM. That's why generally marching music is at 120 BPM so you march to the beat. The result is that some soldiers kept marching at 120 BPM, others adjusted to match the song, and it all generally looked like shit.