Why Bangladesh broke free from Pakistan in 1971

I would like to translate this short story someday to English (from Bengali). The story in short: Ms. Lydia Edith, a British school teacher attended a social gathering of South Asians in London and was wondering why Bangladesh got independence from Pakistan in 1971. In that meet a Bangladeshi student sang a beautiful Ghazal in Urdu which was much appreciated by everybody including a Pakistani professor present there. Ms Edith asked the Pakistani professor to sing a Bengali song. The professor politely refused saying that he does not know any Bengali song. Ms Edith persisted - at least one line? The Pakistani professor turned pale from shame - sorry not even a line. And suddenly Ms Edith knew why Bangladeshis broke free from Pakistan's imperialism in 1971.