Before the concert began, music director Carl St Clair made a strategic switch that gave both Wolfgang Amadeus Mozart and Narong Prangcharoen a better chance of being heard, and ended with a Tchaikovsky Fourth Symphony as splendid as it comes. As the search for a concertmaster and a principal viola continues, the Orchestra sounded richer than in previous years, marginally less svelte, still quick and easy to move, and tuned into their conductor's  physical intensity, eloquence and energy that has become a staple of the Pacific Symphony experience.

Violinist Arnaud Sussmann, Mozart's Third Violin Concerto and the audience were the main beneficiaries of the choice to put Mozart first because otherwise – as St Clair explained from the stage – the audience might have been tempted to walk out during the unfamiliar new piece scheduled to open the concert: composer-in-residence Prangcharoen's Absence of Time. 

Whatever the reason, Sussman's Mozart was a miracle in which St Clair and the Symphony participated in every way. An unusually large complement of strings, though not as large as the Tchaikovsky that would follow after intermission, articulated the crucial opening tutti like a chamber orchestra, the oboes crisp and bright, and when Sussmann entered with his rich deep tone, he acknowledged the orchestra, musically, by making the transition seamlessly smooth as if he had been playing along with the violins all the while. 

From then he, the Symphony and St Clair interacted in a charming, immaculately smooth performance teased out with historically-informed ornaments and trills and turns. It made Mozart more human, more dimensional, more informal, and allowed the audience to sit back and revel in the sounds made by a violinist who has an innate ability to hit the acoustic sweet spot of whatever hall he's playing in.

In the slow movement the orchestra gave an admirably restrained version of the customary hoary pause before the opening melody, after which St Clair, always an adroit and engaged partner, set a perfect temp that let the music breathe, the muted strings still evanescent; Sussmann was glorious leading to Robert Levin's curious cadenza, and just before the end, of course, that little pause again. 

The third movement was full of numerous added touches almost as felicitous as the original score itself, with the violas led by Meredith Crawford full of infectious spirit, and Sussmann playing the succession of mercurial quicksilver roles like d'Artagnan. This was Mozart buoyant, a spring in his step. 

Narong Prangcharoen's brand new concerto for flute, oboe, clarinet, bassoon and a large orchestra with three busy percussionists, gave the audience a bit of shock with its exotic opening rattle out of which the soloists eventually emerged so organically that the idea of narrative flow was abandoned in favor of fifteen minutes divided into three main sections (fast, slow, fast), that explored, according to the composer's notes, time, the world and Einstein. 

This meant lots of percussion, layers and layers of sound and effects from spectral strings to Japanese shakuhachi, overlaid on occasional, sustained patches of conventional musical line. The excellent solo quartet's big moment was an extended cadenza leading to a furious orchestral assault. As the ensuing chaos coalesced into a more primeval place, the soloists playing their hearts out, then one final outburst.

After intermission, Tchaikovsky's Fourth was what the Pacific Symphony under St Clair always delivers: powerful, passionate, immensely involving and urgently played.