The music of "Barbie'quot; has become its own blockbuster, selling 126,000 copies in its first week and debuting at No. 2 on the Billboard Hot 200 albums chart. But overwhelmingly, there has been a drought in zeitgeist-defining film soundtracks. It is hard to pinpoint how long it has been since a soundtrack has dominated conversation. In the current era, most 'successful' soundtracks opt for that.