It wouldn’t have passed muster with Empress Maria Theresa of Austria, that’s for sure, and I’m not just talking about the cancellation of the post-performance fireworks for the start of the Mostly Mozart festival. Far worse than the Barbican’s decision not to disturb the fauna of EC2 was the dearth of musical fireworks in performance — and when it comes to Mozart’s Ascanio in Alba, an unashamedly brown-nosing paean to the great Empress, the results can be pretty fatal.

Less an opera than a series of divertissements, Ascanio in Alba certainly tests to the limit one’s patience with the juvenile Mozart. There’s scarcely a duet or ensemble to be seen amid acres of recitative and numerous serene but undistinguished arias, as the small cast of Arcadians slowly surrender to the inexorable munificence of Venus — aka Maria Theresa — to celebrate the nuptials of her son Ascanio and the guileless nymph Sylvia.

At least the band managed to summon up some festive pomp. Fabio Biondi’s Europa Galante can turn semi- precious baroque into glittering jewels, and they played with all the colour and attack necessary to sharpen Mozart’s pastoral palette. If Mozart’s arias remain largely pedestrian, the scoring shows tints of the greatness to come, and Biondi honed in on the orchestral invention with surgical precision. Tempos were sprightly and alert; Biondi’s silky violin a good counterbalance to the grainy energy of viols and cellos.

But the scorebound singers (rarely making eye contact with one another) made very heavy weather of the vocal material. No doubt the much-missed Sandrine Piau would have provided regal magnificence as Venus, but her replacement, the hard-working Patrizia Biccirè, was too small-voiced and polite to work us up into a royalist frenzy.

Likewise, Carlos Mena’s ultra suave Ascanio had plenty of pure tone, but the Spanish counter-tenor needed to find more ardour and anguish to enliven his passions. Of the remaining characters, only Anna Chierichetti’s accomplished Silvia made an impact, but she foundered by singing with too much taste and not enough spirit. Orchestral finesse apart, this wasn’t an opening night to remember.