I'm not terribly familiar with the show (though I know the overall plot, etc), but I having heard the above songs, I was wondering what part of the show they occur in, what is happening in them, and I guess, what has led up to them being sung?
The Army Song occurs in the MacHeath lair after he weds Polly Peachum and is basically Mac and Tiger Brown reminiscing on their fond days together in the army. I forgot what the Immoral Feelings song was about, but the Army Song is about 2/5 through the show I'd say.
Ha! i was just in a production of Threepenny and we modernized the show, and set in in post new orleans katrina...which actually worked really well, despite what I thought at first. I played tiger brown and we did Army song as a hip hop esque number...(It sounds AWFUL in theory, but if you don't know the show, it worked really well) It was so awkward at first, but in the end it was pretty cool....We changed the style of a lot of numbers...But overall, for a student production it was kind of awesome. http://photobucket.com/" target="_blank"> border="0" alt="Photobucket - Video and Image Hosting">