If the fathers of opera are looking down on Karol Szymanowski’s Król Roger, they will be not so much turning in their graves as open-eyed in astonishment at the directions in which their art form can be taken. Here is an opera whose main purpose is to elucidate Nietzschean philosophy, in particular the contest between the Apollonian and Dionysian (refinement versus base instinct) in Nietzsche’s The Birth of Tragedy.

The founding fathers would be every bit as astonished at the sound world that Szymanowski creates. The orchestral timbre is exceptionally dense and multilayered, engulfing you in ocean waves that roll and break. The instrumentation is rich, but where many composers use complex instrumentation to bring out individual instruments, most of Szymanowski’s music in Król Roger does the opposite, using blended sounds that are constantly shifting. You don’t hear the individual horn or clarinet line: you just feel enveloped by the totality of the orchestral sound.

Kasper Holten’s production, the first for the Royal Opera, further accentuates the conceptual nature of the opera. The opening is the opera's most extraordinary piece of music: a choral crescendo which starts from the faintest of pianissimi and swells to mind-blowing intensity; in Holten’s production, the stage starts in total darkness and light slowly grows to illuminate the features of a gigantic head – most of the height of the proscenium arch. The light is a projection: as the act progresses, it shifts and swells with the music to produce shifts in the expression of the enormous face.

It’s a real theatrical tour de force from set designer Steffen Aarfing, as well as being in full alignment with the intent of the opera, but it’s bettered in Act II. Following on from Act I without an interval, the head is rotated to reveal that in this act, we are literally inside the three levels of Roger’s mind as modelled by Freud: at the top is the superego (an observatory); in the middle, where most of the action occurs, is the ego (a library); at the lowest level is the id, populated by nine dancers in flesh-coloured body suits who writhe in a tangled mass to represent the erotic instincts. It’s potent stuff, the more so because it’s so closely allied to the full intensity of Szymanowski’s music, played sensationally by Antonio Pappano and the Orchestra of the Royal Opera House. This isn’t an orchestral performance where one can pick highlights: it’s the constant power of the ensemble that impresses, especially when the chorus joins in on such blistering form.

The title role is supposedly King Roger, the creator of the Norman Kingdom of Sicily in the 12th century and one of the most successful and enlightened kings of the mediaeval world: as fine a statesman and creator of a nation as he was a warrior. In truth, the simple plot line is not taken from any historical events or people: Roger’s name is simply used as a cypher to which Szymanowski attaches the inner struggle to which even the greatest human can be subject. In the title role, Mariusz Kwiecień  sounded warm and expressive (being a native Polish speaker can’t hurt, in this role), but for much of Acts I and II, he wasn’t producing the volume to cut through the lush orchestration and project the required authority. After the interval, Holten announced that Kwiecień had been suffering from a cold and begged our forgiveness if he turned out to be unable to complete the opera. In the event, Kwiecień seemed to recover somewhat in Act III: it’s only 25 minutes in length, so he must have felt on the home straight. One hopes that he will be back to top form for the remaining performances in the run.

The Shepherd, a Dionysian cult character who leads Roger and his people astray, was sung in a clear and bright tenor by Saimir Pirgu. For the most part, Pirgu’s voice was strong and effective, although the transition to the highest notes wasn’t always managed with total confidence. No lack of confidence was evident for Georgia Jarman as Roger’s wife Roxana: Jarman has the same level of vocal brightness as Pirgu right the way up, and threw her voice around the high notes with aplomb. Kim Begley produced a darker, stronger tenor as Roger’s friend Edrisi.

Król Roger is an opera with amazing music, of which  the Royal Opera Orchestra and Chorus give a storming account. Holten’s production does an impressive job of exploring its concepts – perhaps more psychologically than philosophically. It’s a production well worth exploring – just be prepared to expand your horizons as to what opera can be and mean.