THE light can turn in the blink of an eye in Iceland. Across the bay from Arnarholl, a hill that stands above Reykjavik’s low-lying buildings, a volcanic ridge rises from the sea. Called Esja, its snowy flanks reflect the sun in brilliant white, then moments later flash grey and green, before disappearing altogether under the clouds. The particular quality of Iceland's light is apparent in Harpa, the building that dominates Reykjavik's harbour. Completed in 2011, Harpa houses three concert halls, a conference centre, shops and one of the city’s finer restaurants. Its name derives from Icelandic words for “harp” and "spring". And in providing the country's 60-year-old symphony orchestra with its first ever purpose-built home, it encapsulates the recent re-energising of Iceland's cultural scene.

The hall is touted as a work of art in itself: the “largest glass sculpture in the world”, says Olafur Eliasson, the Icelandic-Danish artist who designed its outer shell. It is made of interlocking glass cells, a few of which have coloured panes that can be illuminated. The result is a building whose skewed angles and monumental scale make it resemble a cliff that, like Esja across the bay, catches the changing light.

When your correspondent visited, a dressy crowd heading to an Abba tribute concert was parting to make way for a mysterious black shape moving slowly down the stairs. In the foyer this "slug" and other members of a Glasgow-based theatre group duly performed a three-hour improvisation. Nearby, stretched along the glass wall overlooking the sea, "Music on a Long Thin Wire" by Alvin Lucier, a veteran American experimental composer, was entering the final phase of its three-day installation. The piece takes the form of a long piano wire that picks up vibrations from the space around it and amplifies them. The Scottish performance, which sounded at times like a death metal song being turned inside out, gave the wire something unusual to work with.

Both Mr Lucier and Asparagus Piss Raindrop, the Scottish group, were in Harpa as part of the three-day Tectonics festival. It is the brainchild of the symphony orchestra’s music director, and is curated in partnership with a similar festival in Glasgow (May 9th-11th). Tectonics aims to accelerate the glacial pace of change in orchestral performing culture, introducing orchestras and their audiences to a more experimental style of music-making in which the “high-art” ambitions that orchestras traditionally express overlap with other contemporary musical genres. The programmes bring established figures in the musical avant-garde, such as Mr Lucier, into contact with lesser known and more local composing talent.

The Icelandic festival certainly succeeded in shaking things up. The first evening’s concert opened with a striking new piece by Pall Ivan fra Eidum, a young Icelandic composer, called “Mirror Neuron System”. It has no score as such. Instead Mr Eidum has made silent videos of himself playing the main orchestral instruments. The orchestra members then mimic the relevant video recording as best they can, producing the sounds which Mr Eidum's gestures seem to intend. The results are in some ways surprisingly traditional, but the blocks of activity—which take the form of basic melodic lines, rhythmic pulses and blocks of both—are interestingly diffuse in their articulation. The same concert featured new pieces from two of the country’s brightest musical talents, Valgeir Sigurdsson, a composer, and Skuli Sverrisson, a jazz musician, as well as Mr Lucier’s orchestral work from 1999, "Diamonds".

The popular festival is testament to the success of Harpa and its commitment to programming the broadest possible range of music. Things did not look so rosy when the project’s original funder—the failed Icelandic banking giant Landsbanki—collapsed. Even when the city and state governments stepped in to see the project to fruition, there was still significant resentment against a project that seemed to enshrine Iceland’s “magic money” bubble.

In the three years since Harpa opened, however, its musical activities have proven successful—vastly more so, indeed, than the commercial enterprises like the shops and the conference centre. Despite significant cuts enforced by the country’s government, audience numbers for orchestral concerts have grown by around 25% and many recognise a concomitant rise in musical standards. The doubters may well be proved right, and Harpa could prove too ambitious a project for an island whose population falls short of 400,000. But, for the time being at least, Icelanders are increasingly looking upon the building’s ever-changing skin through rose-tinted spectacles.