Hearts and Minds, the 1974 documentary about the Vietnam War (won an Oscar for Best Documentary). You can view it here. 2 minutes 35 seconds into it, there’s a huge musical production number with actors-as-soldiers singing and marching (on conveyor belts, so they can march and hold position on the stage). Like, Busby Berkeley joins the Army. What is the source of that? It seems to come from a movie, but what movie?
Panache got there first, but every gay guy over 40’s hand went up as soon as they read that!
I can hear Mr. Berlin singing “Oh, How I Hate To Get Up In The Morning!” just reading the OP…
And a great movie it is, too! I wasn’t aware it had any homoerotic overtones. 
Only in its pedigree…it grew out of Irving Berlin’s Broadway review “Yip Yip Yaphank!”, and you know…gay men and Broadway…
Just that one excerpt alone: Thousands of uniformed men, in a tightly choreographed, over the top Busby Berkeley-style number.
Au contraire! Back then, that was considered to be very butch! 
Not mutually-exclusive.
Thanks! 
I found that whole movie on YouTube – but I can barely hear the soundtrack, for some reason. 