The Gigli Concert is widely held to be Tom Murphy’s masterpiece. Certainly it’s among the most justly lauded of that writer’s works for point of dramatic intensity and sustained control.

The action takes place in the hovel-like office of JPW King (Declan Conlon), an Englishman living in Dublin, an alcoholic and a “dynamatologist”. Dynamotology, we learn, is a discredited form of modern therapy based on pseudo-philosophical principles in which even JPW himself seems to have little faith. To his surprise, however, a mysterious and potentially psychotic client (identified only as Irish Man in Murphy’s script, played here by Denis Conway) arrives at his door, who says he needs help to sing like the Italian opera singer Beniamino Gigli. The drama evolves and erupts over the time period of the next five days, as the sessions progress and the problems of the two men begin to conflict and converge.

From an actor’s viewpoint, the role of Irish Man – with his demonic desire to communicate the troubled facts and fantasies of his life – is presumably difficult to play without slipping into over-exaggeration or emotional farce. However, for the most part Denis Conway makes compelling work of both the destructive agony and the pompous, uneasy self-importance of that character. Indeed the strength of this production rests largely on Conway’s command of exactly those two dramatic extremes, wringing hilarity and devastation from Irish Man’s predicament (and from his incongruous mode of addressing it). That character’s violent needs are darkly operatic, after all, but there is also a deliberate irony (if not comedy) in his turning to JPW’s dynamotologist for assistance in fulfilling them. Indeed, much of the drama pivots on both of those characters’ aptitude for parody in desperate circumstances – the ability of each to dissect or show up the delusions of the other, while at the same time being drawn ever more deeply in by the impulsive power of delusion per se, which the two mens’ meetings only prove.

The chief misfortune of this particular production is Declan Conlon’s half-baked performance as JPW. The nervous wit, and pathetic, endearing fragility of the displaced Englishman is entirely lost in Conlon’s interpretation – an inappropriately suave, only mildly dishevelled affair, which bungles the humour (and completely ignores the English accent) on which much of the play’s tension depends. As a result, whole swathes of the drama are reduced to the kind of monotonous solemnity that serves Murphy’s writing most poorly.

Having said this, the characters of Irish Man and JPW’s sometime lover Mona (Dawn Bradfield) are well handled. In fact Mona, when all is said and done, may well be the most interesting character of the three, though she has the least stage-time. Like the two men of the play, Mona is also happy to mix fantasy and reality in the guise of her much-discussed, but actually fictitious god-child Karen-Marie. However, as the drama unfolds, we discover that Mona has actually been looking into JPW’s sought-for “void” for some time; because of this, and in seeming contrast to JPW and Irish Man, her delusions are deliberately cultivated and easily dropped. On this score, she may be the only honest mortal in the play. She acknowledges her illness, admits her disappointments, and declares her love to JPW on her own terms, and without any need of the translating medium or transforming change that the two men impotently require.

Such illuminations are, however, in the first place to the merit of the script itself. Murphy’s play is a brilliantly controlled mélange, in which every height of yearning seems also to be the butt of its own occasion, in which the often searing facts of life are cloaked or taunted by myths of innocence and redemption, in which the characters are continual exiles to themselves, but also capable of unfeigned intimacy with one another, and in which to sing like Gigli is at once a ludicrous necessity, a passing obsession, and a perennial symbol of those impossible realities the past seemed once to promise – a Tír na n-óg of lost things, which persist in dreams and feelings, stray notes in the air, in a room that smells like “a pig-sty”.

There are endless pleasures and provocations to be found in Murphy’s play, although this production, directed by David Grindley, fails to do justice to many of them. The fact is, The Gigli Concert demands and deserves the best that contemporary theatre can offer. As it is, Grindley’s rendition feels like a tired, but passable rendition of a major dramatic work.