New London — This was pretty much everything you could ask for from an orchestral concert: large-scale musical conceptions, showy displays of virtuosity, gripping moments of emotion and, above all, sonic showpieces that gave proof to why a symphony orchestra is made up of so many diverse voices.

Saturday night at the Garde Arts Center, music director Toshi Shimada led the Eastern Connecticut Symphony Orchestra in a sizzling program of 20th century works, leaving the audience breathless with the shattering finale to Shostakovich's Symphony No. 5. Sharing center stage with Shimada was long-time ECSO principal flutist Nancy Chaput, featured in Christopher Rouse's 1993 Flute Concerto.

This long, five-movement concerto, constructed as an arc with a pair of songlike outer movements, a pair of almost manic scherzos and an elegiac central heart, is built of contrasts, but the one constant Saturday was Chaput's mastery. In the Enya-inspired Gaelic-flavored song movements, her phrasing flowed naturally, almost breath-like, even in leaps of wide intervals. Particularly in the final movement, alone in a reverie spinning melody over low strings, her heartfelt simplicity of statement was hypnotic.

In the wild dances of the two scherzos, where she performed breath-defying feats of ostinato, her ability to fill the hall and command the moment were central to the work's success. This is a complex score, full of the push/pull of dissonance and relief, and Shimada kept the often-raucus sectional play exciting and vivid.

The heart and soul of the concerto is the central elegy, in which Chaput spun an austere musical tragedy over equally spare winds and strings, only to have a warm rush of pure emotion rise in the strings, again and again, to bring comfort. It was a highly theatrical concept and highly affecting performance.

The program opened with a well-paced reading of Barber's Overture to "School for Scandal," and it ended with that vast exercise in orchestral color and thematic ambiguity, Shostakovich's Fifth Symphony in D Minor.

Written in 1937 in a desperate attempt to save not only his career, but perhaps his life, after the composer's music was condemned on the front page of Pravda, this purposefully crowd-pleasing work by the master of parody and sarcasm asks one of the central questions about life in the 20th century: can anything be trusted on face value? Was this most facile and sardonic of composers sincere in music that feels heartfelt, even uplifting — or does it even matter?

Shostakovich was, above all, a technical master whose orchestration alone provides thrills, and Shimada took the Garde audience on a tour of just about everything an orchestra can do. From the opening, uneasy and jagged theme, the string sections were powerful and focused. The movement came to full boil in the development, the motoric rhythms driving incessant canonic repeats that layered through the sections. The ECSO has never sounded better than in this terrifying, militaristic march, that jagged opening theme snarling on steroids. And once again Chaput was in the spotlight, as her sweet naïve flute melody emerged from the bombast.

The goofy Austrian dances and spoofy sendup of a Bruckner scherzo of the second movement provided comic relief, a trio of bassoons conjuring images of big-shoed clowns dancing, an airy obbligato by concertmaster Stephan Tieszen offering sonic contrast.

The one section of the symphony where Shostakovich dropped his guard and showed true emotion is the long, heart-wrenching lamentation of the largo. Here, Shimada drew rich vibrato from the strings as the seemingly endless melody became increasingly liturgical, until the wind ensemble rose to conjure the effect of an organ. Shimada's command of the dynamics in the gut-wrenching final pages gave weight to the electronic celeste and harp paired in the movement's desolate conclusion.

The big booming finale, with its ostentatious embrace of the major, has long been debated. At its premier, the finale was seen as a heroic rescue, but Saturday, it was far more ambiguous.

In the controversial memoirs "Testimony" (considered by many to be a hoax), the composer dismisses the finale of the symphony. "The rejoicing is forced, created under threat," Shostakovich says. "It's as if someone were beating you with a stick and saying, 'Your business is rejoicing …'"

The urgency of the finale, with timpani and bass drum booming, was undeniable. But the effect of the coda, with the incessant keening string figures, was much more one of terror than triumph. Shostakovich probably would have approved.

m.moore@theday.com