Wilton's has made a name for itself as a home for experimental theatre as well as big musicals, and it still carries that underbelly, speakeasy feel – as if you might see a corseted ingénue slipping out of her aristocratic lover's embrace as she takes her place on stage. Only a short walk from Shadwell Overground, Wilton's is easy to get to, neatly tucked away in narrow Graces Alley, and the venue's air of tumbledown gentility is the perfect setting for this darkly atmospheric show.

Ten Plagues follows an Everyman-style journey through plague-riven London, and is based on eyewitness accounts of the 1665 Black Death epidemic, but this is no dry historical document: it examines the idea of plague, from Biblical to modern times. The origin of the collaboration is worth noting: having seen Mark Ravenhill's work almost a decade ago at the National Theatre, Almond asked the playwright to keep him in mind if a part ever came up. Ravenhill did just that and, blending his complex, period-nuanced lyrics with Conor Mitchell's striking compositions, they developed the song cycle.

Marc Almond carries the entire piece with only a piano accompaniment, which works in a perfect unison of complex timing and Almond's unique vocal. Against a striated modernistic background, hauntingly projected onto the walls behind him, Almond performs with ghostly digitised images flitting between the dancing dexterity of his own shadows. The setting and style are crucial, because the songs are not show tunes and there's no recognisable overarching plot other than the fluctuations of loss, despair, death and redemption. Without an interval, and coming in at just under an hour, director Hester Chillingworth obviously knows there's only so much postmodern narrative an audience can handle.

Costumed in oddly puritanical black jeans and shirt, the bewigged Almond is as much an apparition of Cavalier punk as he is the story's narrator, taking the audience through the vicissitudes of one man's survival of 1665, the "season of the witch". As he loses friends, lovers, family and his own grip on reality, he is stripped of his wigs and writhes on stage in a white cap reminiscent of a modern cancer ward or a Delacroix painting of a Napoleonic army sickbay.

This, combined with Almond's own tattoos, eclectic jewellery and swashbuckling white pirate shirt, give him a modern Jack Sparrow panache; and yet his piercing black eyes bear out the pain of loneliness, loss, and the unbearable weight of history. This allows Almond to convey the horror of all plagues – and the panic they spark, whether expressed by witch burning or the gay man's experience of AIDS hysteria in the 1980s.

Whilst the narrative arc is difficult to follow, Mitchell's discordantly brilliant composition is impressively matched by Almond's extraordinary achievement in learning an hour of atonal music that doesn't carry a single conventional tune. How he manages to dip, tuck and fill the hall according to the piano's rousing pulse is perhaps the greatest marvel of all. 

As Almond explains in the programme notes, prior to this production he considered all musicals a matter of "verse chorus middle eight and keep it simple": he did not read music, count bars or understand the rhythms of knowing when to breathe and when to sing. Ravenhill, Mitchell and Almond challenge both themselves and their audience through this piece: Ten Plagues demands (and rewards) a level of commitment and cognisance not required by Les Mis.

One caveat is that the intellectualism of Mitchell's music can make the experience alienating rather than emotionally involving; that said, the piece is cunningly aware of its place within the genre. Very much a director's show, one has to wonder if the raw emotion of the protagonist's descent is overshadowed by the artifice and special-effects fireworks. The clever lighting and projections were brilliant and relevant, no doubt, but sometimes they distract from the central story rather than illuminating it, and it can be hard to understand on a human level what the character is going through.

Horace Walpole, Gothic novelist and 4th Earl of Orford, famously said: "The world is a comedy to those that think; a tragedy to those that feel": Ten Plagues combines both, to different degrees. For a piece on such an emotive subject, it's perhaps too distancing, making you think rather than feel – but it's a significant artistic achievement and a unique theatrical experience.

(Review by Katy Darby and Paul Comrie)

Ten Plagues, at Wilton's Music HallKaty Darby and Paul Comrie review Ten Plagues at Wilton's Music Hall.4