There are many memorable cuts on this soundtrack, and I essentially picked this because it's the longest. Anyway, Komeda's score is perfect for the film -- humorous maybe but definetly very, very creepy.
The main theme of Cul-De-Sac. Komeda's off-kilter jazz sensibility was really perfectly suited to Polanski's absurdist comedy. Like many of the best film scores, it seems absolutely essential to the film. If you like Komeda's style, this track really delivers.
from Cul-De-Sac available on CD - The Complete Recordings Of Krzysztof Komeda, Vol. 13 (Polonia)
The perfect theme to Roman Polanski's underrated comic horror film, The Fearless Vampire Killers. With stacked vocal harmonies, suggesting the background singers at some sort of Bulgarian black mass, floating on bat wings over a very jazzy rhythm section, this song is, at once, very creepy and very funny. I have long believed that Siouxsie and The Banshees came into existence entirely due this influence of this track. (Play it back to back with "Switch" or "Israel" or "Cascade" sometime, and you'll see what I mean.) Stereolab likewise. Broadcast or Goldfrapp could do a brilliant cover of it.
from Complete Recordings Of Krzysztof Komeda Vol 19, available on CD (Polonia Records)
And I am not just including this because it is from Rosemary's Baby, my very favourite film of all time. Well, maybe I am a little - the opening credits where Polanski guides us over the rooftops of the Bramford while Mia murmurs her "la la la"s sets up perfectly the movie heaven that is to come.
Actors usually make a hash of singing (and, of course, vice versa - Bjork is great in Dancer In The Dark but that's all I can come up with), although I've heard that Cybil Shepherd makes a decent stab. But Mia can't fail to impress with her innocent singing voice, keeping in the character of Rosemary even though she doesn't speak a word in this song. Komeda maintains his usual atmospheric wonder, with the sort of piano based joy that gave such a fruitful relationship with Polanski's films.
Lots of others have had a pop at this, usually with some degree of success as the melody is so strong (discounting a dodgy metal version of it by some chancers whose name escapes me). My favourites are Hugo Montenegro's (on Good Vibrations) and Claudine Longet's lyric-added version, Sleep Safe And Warm.