To explain the quality that elevates The Madness of King Lear into the sphere of superlative interdisciplinary theatre, we must look to Federico García Lorca: this transformed Lear burns and shimmers with duende, a Spanish concept that Lorca defined better in the 1930s than anyone has since. Duende is “a power, not a work” – the fusion of expressivity, intense feeling, and a realness that cannot be counterfeited. “Everything that has black sounds in it, has duende”, Lorca wrote, and The Madness of King Lear tears up its black sounds from the depths of the heart, translating them into a performance artwork that begins with visual beauty and then unfolds, flower-like, into a masterpiece of wit and grief, tears and music.

Leofric Kingsford-Smith and Ira Seidenstein play Lear and the Fool respectively. Kingsford-Smith more than equals many full-length Lears, delivering a performance so well-sustained and emotive that it can fairly be described as flawless. Seidenstein is a joy to watch: in addition to wonderful verse-speaking, his background in clowning comes to the fore in several sequences of contemporary dance and mime. These interludes are beautiful to the point of being almost frightening, distinguished by a rich visual purity more usually associated with Japanese woodblock printing. Seidenstein’s physical acting is more communicative than many actors’ words, and its adaptable muscular grace underlines his shamanic role in the piece, as like a loving vates, he leads Lear through the close-crowded forests of the mind.

Lear’s troubled mind is a dynamic prism, presenting Shakespeare’s Lear in a refracted form: the events of the original play begin, halt, and alter before our eyes. Both actors fluidly ventriloquize other roles. This practice is often a stumbling-block in small-cast Shakespeare adaptations, but here this is no hint of making do: what we see before us is not a grown man doing his best to voice a young girl’s part, but a tormented Lear who repeats Cordelia’s words in an attempt to annul them, control them – or, perhaps, to understand them. The play’s wrenching finish, unhampered by reverence for the characters’ original fates, includes Lear’s blinding of his own Fool – who in turn becomes Cordelia, lying dead and blind on the ground as Lear tickles her with a leaf. This moment, which replaces the feather held before Cordelia’s lips in Shakespeare’s Lear, epitomises the interpretation’s dramatic power. There is something appalling about its tenderness, as for long seconds Lear becomes the image of a parent playing with a very young child – only his child is dead, and, more than dead, a chimera played by the Fool. What theatre conjures, we must always lose: that is the shadow-meaning of this ending, alive in its duende, reminding us that the price of all our pleasures is their departure.

It is impossible to overpraise this production: a hugely eclectic and well-chosen soundtrack complements astounding performances and cements The Madness of King Lear’s status as an interdisciplinary masterpiece. Lorca’s duende is “the subtle bridge that unites the five senses with the raw wound, that living cloud, the stormy ocean of timeless Love” – Shakespeare’s Lear lays out a whole economy of love, and in this adaptation it is brought to life with such shining tempestuousness that to watch is to be swept away.

***** – 5/5 Stars

The Madness of King Lear is playing at C venues as part of the Edinburgh Fringe Festival until 27th August. For more information and tickets, see the Edinburgh Fringe website.