Presenting the last Mozart symphonies as a three-act opera for orchestra, as Richard Tognetti and his febrile fellow Australians did on Monday, was always going to be a supreme challenge. It worked, as Boyd Tonkin reported here. Since then, the Barbican's grandiosely-named "International Associate Ensemble" has opened up the repertoire, synchronising with film (on Tuesday) and ending its mini-residency with the kind of vibrant rattlebag for which it's rightly celebrated. How it all added up remains to gel in the mind, but the bonuses were splendid: world-class Australian soprano Nicole Car and string players from the Guildhall School with which whom the ACO has been working.
The first half kept mostly light and vibrant with the core musicians, though the opening was pure, deep theatre: Tognetti assembling the chromatic pitches of the theme which Frederick the Great presented to Bach the greatest as a challenge which resulted in the mighty Musical Offering. Musicians walked on stage sounding the notes ito pile up an atonal nightmare - Tognetti seems to have had in mind a traumatic episode from Frederick's youth - before giving a tense version of the remarkable fugue which is the Ricercar a 6, easing only when the music moves briefly into a major-key light. The cue for one of the far from easy-listening string Sinfonias by Johann Sebastian's son Carl Philipp Emanuel would have been JS's intrroduction to the Prussian king at Potsdam, where CPE was working. Musically speaking, the ultimate justification came in the staggered entries which jab their way into the finale. 
Strong and good vibrations continued in Michael Atkinson's more-than-arrangement of tracks from Sufjan Stevens' 2001 album Enjoy Your Rabbit as the Run Rabbit Run Suite, the rhythmic surpises breaking up exhilarating fast pulses holding up to comparison with Bartók's Divertimento at the end of the programme. Quite how Beethoven's early operatic scena "Ah! Perfido" related escapes me, unless it were to be in the chromatic additions to the final section. No matter; Car was the surprise here, to anyone who hadn't seen how her teenage Tatyana in Eugene Onegin could mature into a more tormentedly impassioned woman. Looks as if butter wouldn't melt, but this is the genuine lirico spinto article, as her track record in the opera houses of the world so far attests.
Only by comparison with the floated top notes of all-encompassing Lise Davidsen in the previous evening's Verdi Requiem could the "Ave Maria" of Car's Desdemona be faulted, but one still wants to see and hear her in more Verdi roles here. Violetta especially, whose dying pathos was essayed in the preceding Act 3 Prelude of La traviata. Conjoined, the two operatic excerpts made the perfect diptych, and a fine showcase for the combined forces of the ACO and the Guildhall players (pictured above in among the ACO), though Tognetti tended to fuss a bit with what could be more direct expression. The collective sound, though, was hugely impressive and unified. Left to themselves, the smaller group might have given a more dancing Divertimento, but Bartok's sombre chordings glowed. Only the ungiving acoustics of the ever-intractable Milton Court killed the depths and heightened the acidity. Trying Kings Place next time might be a better option, but then there wouldn't be the money for the enterprise of the ACO's fabulous time here.
