The party’s guests have been carefully chosen: the murder victim’s father and aunt, his fiance — and Rupert Cadell, played by Jimmy Stewart.
Rupert taught all three boys at prep school, where he filled their heads with dime-store Nietzsche, with a sprinkling of Wilde and Rand:
Intellectually superior people (like themselves, of course) were above the law, you see.
Even murder was acceptable, if the victim was an inferior. In fact, such an act of creative destruction would render the world a better place.
It’s hinted — again, this was 1948 — that Rupert had also initiated the boys (or at the very least, Brandon) into homosexuality.
And indeed, despite the strictures of the era, Rope remains one of the gayest movies ever made pre-1960s.
Both Dall and Granger were gay in real life; so was screenwriter Arthur Laurents, who was sleeping with Granger during filming.
To the amusement of all involved with Rope, words like “gay” and “queer” made it past the powers that be because, as usual, Hitchcock intentionally larded the original script with enough superfluous “offensive” fluff — lines like “My dear boy” — to preoccupy, and ultimately wear down, the censors.
The murder scene that opens Rope is, to modern eyes, campily sexual, and not just because the weapon of choice, that titular rope, suggests bondage; Brandon pulls orgasmic faces and even lights a “post-coital” cigarette.