Not sure I noted all the songs. My stepdad was in the Abraham Lincoln Brigade. He taught us all a basic complaint song:
^^^
1)The biscuits in the army
They say are mighty fine,
But one rolled off the table
And killed a pal of mine.
    (cho)OOOOh, I don't want no more of army life.
          Gee, but I want to go home.
2)The coffee in the army
They say is mighty fine.
It's good for cuts and bruises
And tastes like iodine.
       (cho)
3)The chicken in the army
They say is mighty fine,
But one jumped off the table
And started marking time.
       (cho)
4)The trousers in the army
They say are mighty fine.
Me and my buddy
Can both fit into mine.
       (cho)

Don't remember other verses now, but I think there were a few more. We were about 6yrs old (late 1940s/early '50s) when we learned this one. Looks like there wouldn't have been many he could have taught us.               Tw