We used to have military bands like this come out to "entertain" us on the FOB's. Always drove me nuts for some reason. Even when the BIG name talents came out, I didn't have time for them.
"Put on yer gear and join us on patrol", was what I was thinking, then you may hear some "Rock & Roll".
But it is what it is and I can't really fault them for doing something they enjoy.
Beware the man who has one gun, he probably knows how to use it.