DB here, boasting about Kristin:
Our series on the Criterion Channel  on FilmStruck  continues with this month’s entry, Kristin on M  as an exceptionally rich sound film. She talks about how Lang adapted silent-film techniques to the demands of sound while also using sound to achieve effects that couldn’t be achieved purely through images.
Watching her discussion and the clips, I was reminded of what a precise director Lang was–a unique mixture of stylistic flamboyance and swift economy. You see that mix in silent masterpieces like the Mabuse films, Metropolis, The Niebelungen, and Spione. In various entries (here  and here  and here ) I’ve dwelt on his poised, meticulous compositions that use the entire frame area. Sound gave him a new set of resources for dynamic expression. Rather than becoming more conventional, Lang’s American films seem to subtly absorb the discoveries of M. Examples are the tapping of the “blind” man’s cane in Ministry of Fear and the ominously croaking frogs in You Only Live Once. And the propulsive sound cuts in his last film, The Thousand Eyes of Dr. Mabuse, show that he never forgot that sound could be edited as freely as images.
You can sample a clip from the episode at On the Channel at Criterion’s site. A complete list of the Observations on Film Art series (eleven already!) is here . Go here  for blog entries offering background on those installments.
Thanks as ever to Peter Becker, Kim Hendrickson, Grant Delin, and all their teammates at Criterion.