★★★★☆ Curator James Crabb’s programme gets off to a promising start.

Dreamlike musical microcosms alternated with Argentinean tango in a (mainly) 20th-century journey from Piazzolla to Arvo Pärt and Magnar Åm. In such company Vivaldi stands out a bit, but in fact his Concerto for Violin, Cello and Organ, RV554a proved an invigorating prelude to the rest of the programme. For this, James Crabb’s accordion played the part of the organ, while the Australian Youth Orchestra’s Momentum Ensemble provided the string orchestra. Momentum’s concertmaster Flora Wong revealed a silky sound in her various solos, and Crabb took the first of many opportunities to explore emotions ranging from the severe to the soulful.

Composer Iain Grandage was the host for the evening, and while the stage was being reset after each work, he engaged the audience in witty dialogue. He discussed the repertoire, demonstrated various instruments and techniques, and generally made up much of the evening’s entertainment. This had the inevitable effect of neatly dividing each mood from the next, like switching the aural lights back on between each piece. Hence the concert felt like visiting a series of new worlds, chatting in between times with a sprightly and knowledgeable tour guide.

Piazzolla’s Oblivion was certainly a world unto itself. In this arrangement by James Crabb, it opened in clouds of piano and double bass, hovering around the earthy accordion. Soprano Emma Pearson was its brightest star, shaping the melancholic melody with thrilling intensity and control even in the softest, most intimate moments. When the strings swayed in, the slow tango rhythm was a little obscured, but as Ensemble Momentum warmed to their work it dripped from every bow. In the climax, Crabb played in unison with the strings – this certainly built up the sound, but perhaps did so at the cost of the rhythmic texture, which here became a little top-heavy. But as the music died away into a final dissonant wash of notes (and an accordion glissando), the audience was holding its breath as if seized by the last moments of the spell.

This was the first of several works on the programme, which were not only directed and performed, but also arranged by Crabb. As a whole, his reinterpretations of Piazzolla were sensitive yet daring, embracing the folk and urban lineage of the tango. The first half wound up with his versions of three instrumental works gleaned from various Piazzolla collections. Libertango was a riot of gleeful Latin beats, Romance del Diablo wandered soulfully over the heartstrings, and the percussive La Muerte del Angel brought things to a fierce pitch of exhilaration. Even without a conductor, Momentum, Crabb and pianist Stefan Cassomenos maintained an ensemble of stellar quality.

This togetherness was noticeable throughout the evening. Crabb played facing the audience, but he led the musicians behind and beside him with his expressions and body language, embodying the music’s movement from section to section, instrument to instrument, as he directed and guided it. The works conducted by Ariel Zuckermann were marked by an attention to listening between the notes, enjoying the silence that lay behind each one, drawing out the subtlest sounds. Each phrase was as synchronised as if it was played by a single entity, yet the precision was not pedantic – it breathed like a living creature. The tango rhythms pervading the Piazzolla were so tight, they could have been riveted to each other; but playing between the longest pulse, Crabb in particular could enjoy himself with an almost improvisatory freedom.

Also deserving of special mention was the musicianship of the young members of Momentum Ensemble. Their softer range perhaps lacked some intensity, but their blending and their dynamic and colour changes were spot on, and they exhibited astonishing powers of timbre and technique. Two works in particular highlighted this, and would have presented a problem for any ensemble less well-prepared: Norwegian composer Magnar Åm’s Gratia, and a version of Arvo Pärt’s Fratres for strings and percussion. The first was a searching introspection for harp and strings, with Momentum joined by harpist Alice Giles and conducted by Ariel Zuckermann. Ethereal and sparing, Gratia abounded in sudden mood shifts with a tempo that ebbed and flowed.

Fratres is a long, inexorable crescendo, a chorale of strings punctuated by occasional percussion. As Iain Grandage remarked afterwards, its open texture leaves nowhere to hide – any sonic imperfection will be heard instantly.  At first, the chorale felt suspended in a static non legato, but the climax flowed with creamy vibrato. Double bassist Rohan Dasika showed impressive dynamic control with his ceaseless drone, growing through it so gradually and steadily that it seemed almost unconscious.

As Piazzolla’s Aconcagua Concerto brought everyone together for the concert finale, the conviction grew that James Crabb knows how to pick his themes, his repertoire and his musicians. And UKARIA24 is only just beginning…