Note: Please take the survey to your right if you haven't already. Virginia Danielson, in her scholarly book The Voice of Egypt, cites "Raq el Habeeb" (or, her transliteration, "Raqq il-Habiib") as an example of Kalthoum's use of varying qafalaat, or cadences that served as endings for lines, phrases or sections, for maximum dramatic effect.
It's true: This is a particularly dramatic performance; there's a section near the end when Kalthoum really lays into one repetitive passage that is one of my all-time favorite moments in all of recorded music.
I picked this up, along with most of my Oum Kalthoum collection, at the Nile Deli on Steinway Street. Can't wait to listen to the song? Check out this video, which also has a lot of really great photos: