Before Psycho and North by Northwest, Hitchcock's 1935 thriller The 39 Steps was serving up some of cinema's most seminal moments.  Here is a handful of highlights from the film

1.  The opening

Alfred Hitchcock's innovative style is on display immediately, the first shot spelling out the words "M-U-S-I-C H-A-L-L" with each letter made up of light bulbs illuminated one by one as the camera glides past. 

2.  Oh, that's a MacGuffin

The 39 Steps is the first trademark Hitchcock movie, using many of the themes and story details cinema audiences came to identify with the master of suspense.  The thin veneer of civilisation is exposed with at the heart of the story a spy plot involving an innocent man on the run, in the midst of a "double-chase" with police pursuing the hero, in this case Robert Donat as Richard Hannay, while he searches for the real villain.  It was a template to which Hitchcock would return again and again, most memorably in North by Northwest (1959).  The 39 Steps is also the first of the director's films to employ the celebrated Hitchcock MacGuffin, a plot device of vital importance to the characters but which is of little or no relevance to the actual story, here named in the title of the film. 

3.  Screaming for attention

No other director amassed such a rich array of seminal movie moments, from the shower scene in Psycho to the crop-dusting in North by Northwest.  Most will remember the interrogation of Mr Memory at the London Palladium at the end of The 39 Steps, but the moment the evil Professor Jordan reveals his identity by lifting his hand to show his missing finger, and the rousing speech Hannay gives at a political meeting, are two other notable scenes.  Best of all, though, is the famous sound-match cut as Hannay's landlady discovers a woman's dead body at his flat and turns in horror, her scream merging with the whistling of the train taking the alleged murderer on his quest to prove his innocence. 

4.  The master's comedic voice

The 39 Steps is Hitchcock's most purely enjoyable movie.  The director isn't renowned for laugh-out-loud funny, his one shot at screwball comedy in Mr and Mrs Smith (1941) falling flat, but this film has wonderful comic moments.  The music hall episode which opens The 39 Steps is the finest, replete with wicked humour as the proletarian crowd watching Mr Memory's act descends first into disorder ("Gentlemen, gentlemen, please, you're not at home!")  and then chaos after gunshots ring out in the theatre. 

The first question to Mr Memory ("Where's my old man been since last Saturday?")  sets the tone for a scene full of numerous humorous rejoinders ("Who was the last British heavyweight champion of the world?"/"My old woman"), an increasingly desperate cry throughout of "How old's Mae West?"  in defiance of the act's insistence that he won't reveal a woman's age, and the plain bizarre (a henpecked man keeps repeating "What causes pip in poultry?"). 

5.  Shades of Fifty Shades

Co-star Madeleine Carroll was, in the director's own words, "the first blonde who was a real Hitchcock type".  She was handcuffed to Robert Donat by Hitchcock on the first morning of shooting and he left the pair in that predicament for the best part of a day to go about their business.  As biographer Donald Spoto recounts: "[Hitchcock] wanted to know how many people were discussing the manner in which the humiliated couple had coped with details of a decidedly personal nature."  Hitchcock's unorthodox methods – one 39 Steps film crew member described them to Spoto as "sadistic" – elicited sparkling performances from the couple, including when Carroll, still handcuffed to her leading man, has to remove her wet stockings. 

6.  The ending

The film culminates back on stage, appropriately after so many characters have assumed roles to deceive others.  Charlie Chaplin, another working-class Londoner who went on to world fame, ended his late masterpiece Limelight (1952) in a similar way: Chaplin's movie features a ballerina, Hitchcock's a chorus-line; both end with a life-affirming performance taking place on stage a few feet away from death in the wings.