This programme supplied ample evidence for the Scottish Ensemble's strap-line, “re-defining the string orchestra”. Included were innovative approaches to: commissioning; collaboration with composers; mixing genres and the resultant balancing of the composed and the improvised entailed. Sally Beamish's Seavaigers (Seafarers) embodied the vitality that a collaborative approach can inject into a work. Few of us willingly surrender control; Beamish seemed delighted not only to leave space for improvisation in the music but to collaborate with the two featured soloists, fiddler Chris Stout and harpist Catriona McKay, throughout the compositional process. The three movement piece depicts the beautiful but historically perilous stretch of sea between McKay's Dundee and Stout's Shetland.

The opening “Storm” began quietly with ‘shimmering dawn’ whose fluid harmonies morphed rather than changed. Metre and tonality were similarly ambiguous and the execution of this opening was finely paced. The gathering momentum introduced an infectiously catchy reel whose energised accompaniment involved both counterpoint and parallel harmony. “Lament” began with Stout and McKay in tender duo before the Scottish Ensemble supplied gradually thickening texture. There was some fine melodic harp work here, contrasting with the closing movement “Haven” where, before ‘sight of land’, McKay strummed vigorous chords with her right hand while dampening unwelcome notes with her left. This movement, which had begun with a wonderful pizzicato cello sound before moving onto invigorating detached bowing across the ensemble, chimed with what seemed the work's central metaphor of the relationship between danger and feeling really alive. Coupled with the parallel between the improvisatory and the unmoored, both piece and performance hit the spot. Beamish seemed very pleased as she took her bow.

Scottish Variations was more the result of juxtaposition of movements rather than collaboration. The traditional Strathspey tune Tullochgorum was set by Martin Suckling and the task of furnishing five variations fell to composers who worked in isolation. The order of the variations was decided by Morton and the Scottish Ensemble. I had to admire the element of gambling involved here; imagine had the outcome been five adagios!

As Scottish Ensemble Director Jonathan Morton aired Martin Suckling's increasingly spiky and clustered setting of the theme, I predicted, quite wrongly, that its mixolydian mode and dotted rhythms would render the variations easy to follow. I was delighted to be proved wrong and thrilled by both the performance and the promise of something to explore further at a future date.

Alasdair Spratt's opening variation, beginning with viola, then cello before broadening out, was reminiscent of the finest European string writing - Britten, Bartók, Lutosławski. Stuart MacRae's question and answer format, sporting fantastic cello and bass lines, was quite dizzying. Alasdair Nicolson's thinly ethereal Strathspey gestures were haunting. Anna Meredith's vigorous, cinematic variation housed a dark twinkle of humour embedded in ricochet chords and wonderfully controlled dynamics. The last word went to David Horne, whose thrillingly violent pizzicato chords swirled round the ensemble. Based on the idea of the 1952 Variations on an Elizabethan Theme this piece must have caused its composers to feel the giant shadows of Britten, Walton et al. I feel that they gave a great account of themselves and imagine them to be very grateful to the Scottish Ensemble for such a fine performance.

Moder-dy (Mother Wave) is the Norn name for the constant but invisible current between Foula and Shetland's Mainland which occurs independent of weather. It is also the new title for Stout and McKay's 2013 collaboration, Sunstone. This work showed them at their performance best. There was great joy in the lively moments and sensitivity in the more tender ones. In exposed cadenza moments, there seemed a rhythmic intuition requiring only an implied, rather than stated, first beat of the bar. This freed up McKay, who provided the lion's share of rhythmic input, to enjoy a more syncopated existence. And she really seemed to enjoy performing. Seeing her in action would remind those on either side of the proscenium arch why we all gather.

The opening section (of three) featured a joyous musical device which I first noted in a recording of “Uyea Isle” by Fiddlers' Bid (another of Stout's musical outfits). It involves the sudden removal of instruments formerly supplying pulse. Rather than losing momentum the music takes flight. In this case, the majority of the Scottish Ensemble fell silent leaving Stout in congress with three other violins/fiddles. What a great sound! The second movement featured one of the best two-cello riffs I have heard. The closing movement began with a catchy ostinato and later featured virtuosic harp arpeggios and an excellent duo cadenza.

A very wam reception from this capacity Assembly Rooms audience was rewarded with Michael's Wood, a beautifully played lament named after a memorial wood in Shetland.