At first the scene is quiet: Janet Leigh steps into a shower at the Bates Motel, finding relief under the warm water. Then the translucent curtain reveals an approaching figure, who whisks it open with one hand while brandishing a knife in the other.

And the music begins.

The slashing shrieks that follow are some of the most famous musical notes in film: synonymous with horror and still frightening enough to make any veteran thrill-seeker tense up.

At David Geffen Hall in Manhattan, those high notes — Bernard Herrmann’s murder theme for Alfred Hitchcock’s “Psycho” ­— will be struck from the violin section of the New York Philharmonic, which is presenting the movie on Friday and Saturday with a live soundtrack, as part of its popular Art of the Score series.

Also on offer, on Wednesday and Thursday, is Steven Spielberg’s “Close Encounters of the Third Kind,” whose restrained soundtrack by John Williams contains another famous theme: the five notes used to communicate with alien visitors.