It's a truism to say that Peter Brook's film King Lear is a masterpiece. But what is a masterpiece? Saying this of a work can be a way of not looking at it: the artwork becomes "timeless", a glazed exhibit in the museum of our cultural self-regard. It turns into a monument.
Thinking this over after watching Brook's film recently, it seems to me that when I say something is a masterpiece, I mean that its achievement is not that it rises into some lofty empyrean sphere where history no longer exists. It's a masterpiece because it does the opposite: because it makes a gesture so potent that it seems to draw all human experience into its gravity, because it reaches deep into individual and collective memory and hauls experience, naked and bloody, into the present.
Or, you could always try James Earl Jones's famous rendition in 1974, performed live in New York's Shakespreare in the Park.
If you're pressed for time, here is Kate Beaton's comic version.