Its director, Marion McClinton, tells John Lahr in a programme profile about Wilson, "It's August's language - the rhythm of hurt, the rhythm of pain, the rhythm of ecstasy, the rhythm of the family - which sets him apart and is why we call him the heavyweight champion." And it is precisely those insistent and complementary rhythms that are so meticulously and movingly caught by the championship heavyweight cast that McClinton fields in this production.
These actors, with the kind of totally inhabited and uninhibited realisations of their characters, are not just completely in the moment of the play's action but also in its space and place. As beautifully rendered in the set design of David Gallo, that's the dingy office of an unlicensed black Pittsburgh cab company in the late 1970s, run by Roger Robinson's Becker, and facing imminent closure.
The classic work play that follows - in which a vividly realised workplace environment becomes the setting against which everyday and epic conflicts can be spun out - has poetry as well as potency in the extraordinary detail, both of the magnificent performances and the tremendous writing.
Every interaction, large and small, is a study in human behaviour, whether concerned with repaying a 30 cents debt for a cup of coffee, or a bigger betrayal between a father and son that occupies the centre of the play. I salute the whole company who are here for a limited run of 34 performances only, and demand to be seen.