By coincidence, two of the UK’s leading chamber groups, The Hebrides Ensemble and Psappha who both regularly perform new music are 25 years old. This concert, part of a short tour, showcased players from both ensembles featuring a startling new commission, a tribute to a composer who supported both groups and who left us this year, and as a final treat, a performance of Schoenburg’s astonishing Verklärte Nacht in its original sextet version.

David Fennessy’s Panopticon, commissioned by both ensembles, received its première on this tour. It is scored for string sextet and a concert cimbalom, an instrument from Eastern Europe akin to a hammered dulcimer, but the size of a baby grand piano and trapezoid in shape. A panopticon is an arrangement of prison cells in a circle so that any prisoner can be observed at any one time, the sinister watcher portrayed by the cimbalom like a strict commander with an unvarying insistent regular beat. Tim Williams thwacked the beater hard on the wooden body which allowed faint harmonics to emerge, eventually echoed by each string player in turn strumming chords in time, so violent it was difficult to gauge the pitch. Eventually the cimbalom sounds more conventionally, but always a menacing steely edge present, the sextet reacting in cycles and loops, fading away to ever rising harmonics and a lone cello bowing the last note off into the ether.

Sir Peter Maxwell Davies was a huge influence on both groups, and his passing this year in Orkney was marked by two pieces, The Last Island written in 2009, and an arrangement by David Horne of his popular Farewell to Stromness for strings and cimbalom receiving its first performances on this tour. There are two tiny islands, the Holms of Ire, accessible by foot at low tide from the house where Maxwell Davies lived on Sanday, one of the northerly Orkney Islands. The composer imagines the souls of the sailors wrecked on the rocks over the years contrasting with the deep peace of a land which might be at the edge of the world, dotted through with fragile wild flowers as the sea incessantly ebbs and sucks. The music, for string octet, is ethereal yet restless, glissandi set against robust pizzicato, the players at one point looping in tone cycles, bowing harshly almost on the bridge then softening towards the fingerboard. With unresolved chords and phrases there were moments of beauty too, a haunting viola solo over hushed sustained strings, and soft high violins over plainsong fragments woven into this Orkney tapestry, a hint of Ave Maris Stella perhaps sung by the monks who once lived here. The music was accompanied by a film of the islands by Tim Williams, mostly shot in July 2016, but some footage from 2014. Filmed in calm sunny weather, it showed the rugged remoteness and spellbinding beauty which worked its magic on the composer. In the final shot, a lone figure wanders along the beach and the music faded off like spindrift into the wind.

More familiar as a piano piece, and one which Maxwell Davies played at the funeral of Orcadian poet George Mackay Brown, Farewell to Stromness was beautifully arranged for the sextet and cimbalom, the tread in the bass line not too mournful, the lovely simple tune shared amongst all players like an ancient slow elegant dance, the music slightly blurred at the edges as if by tears.

The musicians never sat in the same arrangement twice in this concert, allowing players from the different ensembles to play dominant roles. For Arnold Schoenberg’s Verklärte Nacht The Hebrides players took charge, Catherine Marwood’s gorgeous viola playing shining through the rich chromatic soul music which makes this piece about strangeness, love and forgiveness in a moonlit wood so moving. Richard Dehmel’s poem on which the work is based is a simple story of a man and woman in a wood as she confesses that she is carrying a child from another man she did not love. The strings bit into a deep warmth for the moonlit wood like slow footsteps, turning dramatic as the story unfolds with turbulence. As the man thinks on his response, the strings are ponderous and tender with a piercingly tender cello solo from William Conway. The music shimmers as the man forgives the woman, they kiss and walk on. Verklärte Nacht was Schoenberg’s breakthrough piece yet it had a difficult reception in Vienna with its ‘forbidden chords’. To modern ears, it is romantic and lush, even cloying with touches of Brahms and Wagner, yet this performance concentrated firmly on the storytelling, a fine birthday celebration for two excellent ensembles who continue to make waves.