There's an interesting moment in the ART's Don Juan Giovanni (image below) in which Moliere's Don Juan and Sganerelle check out a drive-in movie - only to find their counterparts in Mozart acting out the opening scenes of Don Giovanni, the opera, onscreen. It's a neat conceptual trick, made all the niftier by the fact that the Don Giovanni cast is also onstage - being filmed live for the feed to the screen. But therefore, of course, the Moliere characters wind up on screen as well; for a moment stage and screen seem to merge, and with a postmodern poof! Mozart's Don Giovanni, Leporello, Donna Anna, et. al., are all "onstage" at once, interacting within the same medium.
Okay, this idea is not entirely new - at least not to those who've seen The Purple Rose of Cairo, much less Sherlock, Jr. - and its ramifications, alas, are soon dropped from the tedious antics of Don Juan Giovanni. But for a moment the production cleverly addresses the issues I thought might be explored in the Huntington's production of The 39 Steps, which claims to evoke Hitchcock's classic film on its stage.
A collision between stage and screen at this level should fascinate - only the Huntington stage production never scratches the surface of Hitchcock's method, which is to move the focus of our subjective "identification" at will (he once described this technique as giving the audience the sense of a chase from the perspective of the fox and the hounds at the same time).
The long clip above has several brilliant sequences, but perhaps most apropos to this discussion would be the "scene" about two minutes in, where Robert Donat overhears his companions reading about his case in the paper - and then attempts to judge from their expressions whether or not they've recognized him. One seems to smile at him with secret knowledge - or does he? The sequence culminates with a tracking shot (which Hitchcock would spend his career extending and perfecting) that follows Donat as he marches out to an officer on the platform to see if he'll be identified. This is the kind of sequence which, one is tempted to assume, would be impossible to replicate on stage in its step-by-step development (indeed, I think the Huntington skipped it) - but something of its essence might be conjured using screens and the sleight-of-hand displayed by Don Juan Giovanni.
The cinema has long been held to be the realm of surrealism and dream-life, while the stage has historically been viewed as a platform for communal self-awareness. Is there a middle ground between the two? Shakespeare, of course, deployed a "cinematic" mix of asides and soliloquies - his "camera" swings from panorama to detail to internal mental state without warning, and with utter aplomb. But he never "moves" through an environment - particularly not a fantastic one - subjectively, as film can. Is such an effect possible on stage? That's the question I wish had been answered, or at least addressed, by The 39 Steps.