Oh yes, I remember this movie (Joseph Cotton, Alida Valli, Orson Welles, Trevor Howard, ...).
I can't forget the zither music of Anton Karas, which seemed to reflect and comfort Viennese "melancholy" in the past - with a touch of Hungarian "longing" in a very dark, sad urban jungle of crimes, hatred, poverty, destruction, treason, humiliations, murders, theft and abuse, wasted people, their feelings and fears.
Very impressing and an insight into tortured, perverse, desperate, crushed and split souls.