Arnold Schoenberg’s Gurrelieder is a work requiring huge forces to perform, wheeled out on the most special of occasions, here not only closing the 2016 Edinburgh Festival but marking a final farewell to Donald Runnicles as the BBCSSO’s Chief Conductor. He will be back on occasion as Conductor Emeritus, but this ram-packed performance in the Usher Hall with an orchestra of 138 and chorus of 170 marked the changing of the guard and a festival finale in splendid style.

Tell someone you are going to two hours of Schoenberg without an interval, and you might get a pitying look, understandable as the composer is better known for his more avant garde twelve-tone and atonal compositions. Written as a song cycle for piano, tenor and soprano at the turn of the century, Schoenberg orchestrated and developed the work, a lush romantic setting of the unhappy tale of medieval Danish King Valdemar IV and his mistress Tove from the Danish novelist Jens Peter Jacobsen. Begun in 1900, and ten years in the writing, it is a fascinating glimpse into the different influences on the young Schoenberg – initially Wagnerian but latterly owing more to Mahler with an occasional Richard Strauss chord change along the way. By the time this work was performed to an adoring Viennese audience in 1913 Schoenberg had moved on to modernism, but we are nevertheless left with a thrilling, monumental and passionate piece of music.

The story of King Waldemar’s love for his beautiful mistress Tove is played out in nine songs, sung alternately and linked by orchestral passages. They meet in secret at Gurre Castle, but Queen Helwig is having none of it and poisons Tove, the story related by the Wood Dove. Waledmar curses God, warned by a Peasant, is condemned to roam with the undead in a savage night-time hunt accompanied by Klaus the Jester until he is reunited in death with his beloved Tove as the sun rises on a new day.

The music is dense and lush, rippling initially in a way only 8 flutes and piccolos can in a 25 strong woodwind section including bass clarinets and contrabassoons. In the extended brass some horn players doubled on Wagner tubas, while a rare bass trumpet and contrabass trombone produced some sock-trembling moments. A huge string section, four harps and an army of percussionists provided a truly thrilling sound. The climactic moments were immense, Runnicles using a huge score, turning each page like stripping a bedsheet, brought out the softer side too, generally balancing the sound sensitively to allow his soloists to soar. He had a lot to look after, and a steady no nonsense beat given straight ahead for all to see was a sensible approach, but he allowed himself more animation in the big moments, both feet off the ground at one point.

Giant orchestras call for big voices with Wagnerian experience. German soprano Anja Kampe and New Zealander Simon O’Neill, a true Heldentenor, were the two lovers, either side of Runnicles, reminiscent of Tristan und Isolde and soaring above the sweeping music. Kampe’s voice opened up gloriously in “Du sendest mir einen Liebesblick” while anguished O’Neill, who had the harder task, fought valiantly against his tormentors – a thrilling voice but sometimes overwhelmed in the melee behind him. Scottish mezzo-soprano Karen Cargill has been singing more Wagner of late and she had the pivotal Wood Dove role completely nailed, in truly magnificent voice, spitting out the words in passionate storytelling in a high drama performance. Fellow Scot Iain Paterson, as the Peasant, and Anthony Dean Griffey as a characterful Kalus the Jester were luxury cameo casting. Thomas Quasthoff, appearing behind the percussion took on the Sprechstimme role of The Speaker, almost singing and clearly relishing the onomatopoeic wordplay.

The large Edinburgh Festival Chorus, with extra men drafted in from The Royal Conservatoire of Scotland and the Royal Northern College of Music had over an hour to wait from warm-up to performance, yet they were immense, not only in volume but in quality of sound and diction. With the sheer density of several choirs each divided in four parts, it can be overwhelming to take in, but the moment when the sun rises at the end was an astonishing glorious wash of noise.

When the silence finally came, Runnicles, arms aloft successfully held the moment before the applause erupted for soloists and orchestra. Chorus master Christopher Bell – surely the busiest man in Edinburgh in the summer – in the trademark sparkly jacket we have come to love was roundly cheered as he brought the singers to their feet. Yet this evening belonged to Runnicles, who finally returned alone to the podium for deserved special acknowledgement.