I know this may be an obscure question, but...

[loyal1]

in the movie Blue Velvet which I saw again a few days ago, his mother and grandmother are always watching some black and white creepy type movie or movies.  all I can remember is the eerie music and a shot of a mans feet as he creeps slowly up the stairs.

Anyone know what movie or movies they were watching???

[JohnL]

The IMDB page for Blue Velvet lists the following as being referenced in that movie;

Un chien andalou (1929)
Wizard of Oz, The (1939)
Shadow of a Doubt (1943)
Love Letters (1945)
Rear Window (1954)
Vertigo (1958)
Mon oncle (1958)
Psycho (1960)
Scorpio Rising (1964)
All My Life (1966)

It's not guaranteed to be one of these, but sometimes they list movies that the characters in a movie are watching (like Evil Dead in A Nightmare on Elm Street), so there's a good chance that it is. Most likely, it's Psycho. It would make a suitably creepy movie for them to be watching, but is well known enough that a lot of people would probably recognize it.

[Mr_Vindictive]

Yeah, I'm going to have to agree with JohnL.  It's been a while since I've seen Blue Velvet, but after reading your post the first thing that came to mind was the police officer walking up the stairs in the Bate's home.