In the Trevor Nunn documentary Gielgud remembered the time he "tried to direct" Richard Burton in Ha

From the book John Gielgud Directs Richard Burton in Hamlet, which is actually a transcript of the rehearsals, and extremely interesting! This was too funny not to share:

Gielgud: And I do beg you, Linda [Ophelia], in the mad scene, to wear your blouse right open. Modesty aside! Don't tie it in front. I suppose it would be too much for not to have it at all, just to wear the brassiere and the skirt. Do you think that would be too much? Would that embarass you?

Linda Marsh: Yes.

Gielgud: It would. Well, perhaps it wouldn't be so good. You might look like the Playboy Bunny of Elsinore. And Rosencrantz, don't come in with that empty scabbard in the "Hide fox" scene. Leave it offstage. It looks most indecent, that white flexible scabbard, hanging like that.

Over-dull, definitely

If you can believe it, this production was actually controversial in 1964 for it having the absolute minimum of scenery, props, and set, along with the actors wearing rehearsal clothes (carefully chosen, but still ordinary 1964 clothes).

Gielgud: Well, the first scene didn't really work. I'm sure it disappointed them. And then in the second scene they were staggered by the clothes.

Burton: Well, we suspected it would take them time to get used to the clothes, but last night's audience was particularly unsophisticated.

Gielgud: Or oversophisticated.

Burton: Or over-dull. They didn't know Hamlet at all. Elizabeth told me some of the comments she heard about the play and they're extraordinary! Like the old lady who said, "Isn't it full of quotations?"