The fool can always be relied upon to tell the truths from which others shy away. And in the early years of Nazi rule in Germany, composer Karl Amadeus Hartmann (1905-63) set about using the figure of a simpleton to warn of the dangers ahead. He based his opera Simplicius Simplicissimus (which might be translated as ‘The simplest of simpletons’) on a novel by Hans Jakob Christoffel von Grimmelshausen about a boy who survives the sheer destructiveness of the Thirty Years War in 17th-century Germany through his lack of wits. By the time Hartmann had completed the first version of the work, in 1935, the composer had gone into self-imposed internal exile, refusing to have anything to do with the musical life of the Third Reich, and the opera wasn’t heard until the late 1940s. It has since been performed intermittently in Germany, and indeed has two new productions scheduled there this season, in Bremen and Augsburg. But it had not, however, been staged in the UK until this production by the enterprising Independent Opera.

This picaresque work is touching and brutal by turns, words that might also describe the brilliance of the music of this percussion-heavy score. Above, all it is unremitting in its anger, drumming home the loss of two-thirds of the German population during the Thirty Years War, the savagery of the soldiery and the tyranny of the powerful. The mostly tonal musical language is difficult to place within any ‘school’, but has allegiances with the likes of Stravinsky, Hindemith, Krenek and Weill, and ranges from Bach-like chorale (intriguingly the opera is exactly contemporary with Berg’s Bach-quoting Violin Concerto) to furious march, slitheringly ominous strings to playful folksiness – wide-ranging, yet somehow all of a piece in total effect.

The role of Simplicius, as the boy is named by his hermit protector, is given to a soprano, and for this belated UK première Stephanie Corley made the role her own, as athletically boyish in her acting as she was focused in her singing. Otherwise, apart from the mute role of a woman subjected to sexual humiliation by soldiers and rulers (dancer Chiara Vinci), the cast is all male, comprising a chorus-like ensemble playing everything from sheep to soldiers to rebellious peasants, plus a number of cameo roles, the most prominent being Adrian Thompson’s sympathetic Hermit, William Dazeley’s strutting Soldier and Mark Le Brocq’s libidinous Governor. There wasn’t a weak link among them, and the diction in projecting David Pountney’s often gritty new translation made the use of surtitles (not always matching the sung text anyway) superfluous. Hartmann’s score was vividly brought to life by the musicians of the Britten Sinfonia under the direction of Timothy Redmond, with some pungent sound from the strings and lively solos from the wind.

Nate Gibson’s solid but straightforward design of a war-ravaged landscape, including simple but effective projections, provides an effective platform for Polly Graham’s terrific staging – a thrillingly physical tour de force that matches the intensity of music and drama. She marshals her cast with great mastery, from regimented soldiers to the tower of humanity representing the Ständebaum, the tree that for the boy reflects the hierarchy of society. She also makes full use of the rather cramped space of the Lilian Baylis Studio’s black-box space, with singers circling the orchestra and audience. In all, it would be hard to imagine a better introduction of this fascinating and gripping work to British audiences, and one would hope that it could outlive its brief run of four performances to be seen further afield. My only criticism of the whole enterprise is that it could have worked even better without an interval breaking up the momentum of its forceful, 90-minute journey.