New London — It’s not often that a big orchestral composition gets its North American premiere more than 80 years after it was written, but since Toshi Shimada took over as music director of the Eastern Connecticut Symphony Orchestra, the unexpected is becoming the norm.

Saturday night at the Garde Arts Center, the ECSO gave stirring performances of two well-known, powerful works, but everyone left talking about that U.S. premiere and the soloist who brought it here, pianist Gary Chapman.

Chapman is one of the region’s best-known musicians, a keyboard polyglot who performs and arranges jazz, takes national tours playing everything from lieder to Broadway and has acted as ECSO principal pianist for years. A frequent pre-concert speaker, he is one of the winning personalities in the orchestra in many ways.

So it’s entirely fitting that when Shimada asked Chapman to pick out a piano concerto to perform this season, the Norwich resident selected not an audience favorite showpiece to grab the spotlight himself, but an unknown piece that placed the piano firmly within the orchestra, first among equals, not out front. It was a choice as flattering to the orchestra as to the soloist, which speaks volumes about Chapman.

This not-a-concerto was British composer John Foulds’ Dynamic Triptych for Piano and Orchestra. Foulds was one of that early 20th century generation of British nationalist composers and was best known in his day for lighter fare, like Arnold Bax or Hubert Parry. Chapman discovered Dynamic Triptych on a BBC broadcast of the 2010 Proms, which was remarkable enough, since it is almost never performed.

On Saturday, Chapman, Shimada and company rattled the rafters at the Garde with this sonically dense and explosive work. It may not be the most memorable of compositions, but as Shimada said in introduction, “it’s a dynamite piece.” The three-movement work is very much of its time, evoking at times Prokofiev, Ives and Barber — which is to say, some of the best of the 20th century.

The opening movement, called Dynamic Mode, employs a seven-note modal scale of Foulds’ invention that reflects his lifelong interest in Indian music. Chapman attacked its opening two-handed octaves and quickly developed a percussive interplay with staccato brass figures. From a wash of odd, seven-notes scales, the score handed off to insistent stalking brass figures. As the brass churned (they ECSO brass section was the other star of the night) and Chapman had a long rest, he rocked on his bench in obvious pleasure, delighting in the sound like the rest of us. It’s a feat to make a 10-minute movement without harmonic variety succeed, and they pulled it off with a flair.

The slow movement was the most intriguing. Chapman lovingly drew the long melodic lines, redolent of Rachmaninoff and Barber, as the string accompaniment seemed to collapse around him, tumbling through quarter tones to evoke Eastern exoticism. Here again, Chapman led the orchestra to its fierce crescendos and sat back to enjoy the performance around him. Trumpet principal Julia Caruk played an icy and haunting muted obbligato before Chapman’s return with glittery figures for the winds to ride upon. Shimada whipped up a mad, dense orchestral episode, like one of those Ives canons gone awry, before Chapman wound it down with delicious restraint, lingering teasingly in the beautiful final measures.

The last movement, Dynamic Rhythm, opened with Chapman playing off the percussion and weaving brilliant passagework over muted strings. Shimada brought the dense and exciting orchestration into full bloom, with Chapman often inaudible beneath the big noise. It was all excitement, all fun and the audience loved it.

The concert opened with a measured and stern performance of Liszt’s 1851 tone poem Les Préludes. Shimada crafted the arc from thrilling Wagnerian start through a lilting dance to thrilling Wagnerian finish beautifully in the swashbuckling 15-minute piece, which featured some remarkably light and supple playing by first French hornist Bryce Nakaoka (who would also shine in the symphony to follow).

The program ended with a rich and vibrant reading of Sibelius’ beloved 1902 Symphony No. 2 in D Major. Shimada drew out a dark-toned, burnished sound, and it seemed the right side of the stage — the cellos, bass viols, violas and the brass — carried the load, despite fine playing throughout by the horns, winds and violins.

This symphony, a work that defined Finnish music for many generations to come, is made up of snippets and fragments, short ideas that converse until the expansive finale brings it all into focus.

Shimada did justice to this major work, despite its difficulties of scale and shape. The darkened, lower-register oboe voice of principal Carla Parodi rose time and again out of the dark woodwork, and the sectional play of fragment after fragment was sharp, smart and affectionate toward this score.

We’ve come to expect nothing but the best from the ECSO, and Saturday, they did not disappoint.

m.moore@theday.com