Four years ago, the ACO mounted The Reef, a fusion of film and music where moments of synchrony alternated with places where one or other art-form dominated. Mountain is clearly its successor: another film project involving scenes of nature peopled by extreme-sports enthusiasts, screened while an eclectic soundtrack is played live by the orchestra. A collaboration between Jennifer Peedom (credited as writer, director and producer), Renan Ozturk (cinematographer), and the ACO’s own Richard Tognetti (musical supervisor), there was no question but that Mountain had been crafted as much around the music as the images. The resulting multi-media experience was by turns moving and thrilling, with an admixture of that delicious terror associated with the sublime and the occasional relieving opportunity for laughter.

Needless to say, there were several differences between the two films. The sight of production company logos and sponsored advertising at the start made clear the more commercial nature of this project. Unlike its predecessor, Mountain had a voice-over (provided by William Dafoe), which pointed up the thematic significance of the accompanying images, and helped shape the narrative. Moreover, the nature of the interaction between music and what was shown was, of necessity, going to be different. In comparison with the rolling waves and breakers featured in The Reef, the unshaking permanence of mountains offers fewer obvious homologies to the temporal art of music, with its ever shifting surface.

There were several ways in which the visuals themselves provided movement. There were plenty of pan and tracking shots across landscapes, as well as sequences where time was radically sped up (night became day in seconds, trees visibly sagged under rapidly accumulating snow, and the rising and falling ground level in one scene made it seem as if the landscape itself were breathing). Most obviously, the focus on human activities in these elevated spaces allowed for movement aplenty, whether it was skiers, base jumpers, bikers or the like, several of whom seemed to have death wishes.

Not that composers have entirely shied away from musical representations of high places: from Liszt (Ce qu’on entend sur la montagne, the so-called Mountain Symphony) through D’Indy (Symphony on a French Mountain Tune) to Strauss (the Alpine Symphony), the romantics embraced such spaces as occasions for grand monumentality. However, as was explained in the excellent program note by Joseph Nizeti (composer and music supervisor on this project, and, as it happens, a former student of mine), early attempts to match the images with Strauss’ music were found to be contrived. Consequently, the team looked to less obvious sources.

The majority of the film was supported by adaptations of existing works ranging chronologically from Vivaldi to Pärt and with linking sound cues composed by Tognetti. Diverse though this seems, the source material was less varied than for The Reef. However, as if by compensation, Tognetti’s own music showcased a variety of styles, including quasi-minimalist stasis and a hard-rock offshoot featuring the vocals of violinist and part-time singer Satu Vänskä (I couldn’t help feeling that a more guttural, shouty sound might have been a more apt match for the amplified power chords here).

The five nearly conjoined excerpts from Vivaldi’s concertos were delightful, the choices ranging from the obvious but effective (the opening movement of Winter, played with a particularly gritty, sul ponticello effect as climbers slipped from rock faces and dangled vertiginously above the void) to the wittily perverse (the tempestuous final movement from Summer as expert skiers dodged through snow-laden trees in slow motion). An abbreviated performance of Chopin’s dreamy D flat major Nocturne (played with sensitivity by Tamara-Anne Cislowska) was paired with historic footage of early climbing expeditions, Grieg’s livelier Präludium from the Holberg Suite with a modern plane in flight.

Continuing the ACO’s love affair with slow movements by Beethoven, two were featured towards the end of the film. In the second movement from the Violin Concerto a spotlight was on Tognetti as soloist, with computerised falling snowflakes recycled endlessly on the screen. Tognetti’s entry pushed the tempo wilfully forward, although once an equilibrium was struck there were many lovely moments, including the imaginative embroidery of some of the pauses.

Cislowska was the focus in the Emperor Piano Concerto, whose full slow movement was heard in tandem with a glacially slow pull-back from a single peak. The clear priority of the music in both cases was unmissable, bearing out Tognetti’s remark that “the Beethoven … transcends it all”. This was another sort of sublime – not the brassy exaltation of Strauss, but a deeper, more inward content. “What curious performances we put on with the mountains as our theatre,” the voice-over remarked in a moment of surely intentional self-reflection. As a project, Mountain may indeed be a curiosity, but an inventive and broadly effective one.