the shoulder shaking singer

Can you give a bit more detail about the musical number? I've seen this film numerous time and offhand don't recall any female singer noticeably "shoulder-shaking?"

It's been 10 years since the question--but if anyone is curious, I think the singer shaking her shoulders is Patty Andrews, the lead singer of the Andrews Sisters trio. I'm watching the movie now on TCM, and after her comedy bit about the marine wearing her out on the dance floor, she was singing and kept flinching or shrugging--shaking her shoulders.