"The guys of the Cahiers du Cinéma came to me. They wanted to analyze the connection between the plate swinging at the beginning of 'Blood and Black Lace' and the telephone falling to the ground when Eva Bartok dies. I didn't even remember how the movie ended." (Mario Bava)
Cinematographer Ubaldo Terzano and composer Carlo Rustichelli make for a formidable pairing here. The sleazy jazz score is marvelous and compliments Terzano's frames of primary hues perfectly to help create an atmosphere and mood unequaled in the Giallo sub-genre. To criticise the script and the cast would almost seem cynical in this case such is the sensory delights of Mario Bava's dreamy masterpiece.
Full disclosure: I was very drunk when I watched this and when the killer was revealed I didn't know who they were in the context of the film. So I really have nothing to contribute, other than I was bored by the plot which was really there to service the deaths anyway.