The soundtracks of both games jarringly counterpoint the brutal actions of scavengers in the Capital Wasteland and Rapture. Inhumanity and desperation is hauntingly accompanied by songs by songs by Billie Holiday, Cole Porter, Ella Fitzgerald, the Ink Spots, and the Andrews Sisters. That both soundtracks are comprised of songs, which almost exclusively belong to a time associated with values, decency, and decorum, is, of course, intended to be ironic and also serves as a means of emphasizing just how rotten the world has become since a time so idealized in the American imagination.
via popmatters.com