CAMBRIDGE - Radius Ensemble kicked off its 10th-anniversary season on Saturday with a dark-to-light program exhibiting the group's characteristic features: wide-ranging repertoire; energetic performances; and a casual ambience, including spoken introductions to each piece (which, also characteristically, ranged from illuminating to awkward and redundant).
Some of the dusky hue of Beethoven's C minor String Trio (Op. 9, No. 3) resulted from the venue: what little shimmer there was in violinist Jae Young Cosmos Lee's tone was sucked up by Killian Hall's infertile acoustics, and the rich middle ranges of violist Stephanie Fong and cellist Miriam Bolkosky predominated. A sharp, heavily accented approach emphasized the music's assertiveness, the 17-year-old Beethoven tackling high-Classical forms with youthful pugnacity - though the surprise soft ending was dispatched with appropriate offhandedness.
The Holocaust themes of Osvaldo Golijov's 1991 "There is wind and there are ashes in the wind," incorporating texts by Elie Wiesel, conjured darkness even before the start - pianist Sarah Bob's prefatory words tasked the piece with gravity and responsibility. But the music proves intriguingly elusive, evoking fragmentary remembrances in the gaps between imagined and actual sounds: The piano tries to blur its attacks into a rushing mist, while the clarinet (Eran Egozy), in its highest register, gives the impression of an overtone to a lost melody. WBUR radio host Robin Young recited Wiesel's words with graceful restraint, leaving bare the power and limits of recollection and language.
The shade lifted after intermission with Augusta Read Thomas's "Pulsar," a bright violin monologue composed in 2003. Lee fared much better here than in the Beethoven, in complete command, a performance bursting with color.
The concert closed with Leos Janácek's 1924 "Mládi" ("Youth"), in which the composer at 70 fondly recalled his childhood. The unusual addition of a bass clarinet (Rane Moore) to a standard wind quintet - flutist Joanna Goldstein, oboist (and Radius's director) Jennifer Montbach, Egozy, hornist Anne Howarth, and bassoonist Carlos Arias - resulted in a fat, rustic timbre that the group reveled in. Janácek's stomping dance music thrummed with zest, though the vigor robbed softer sections of lilt. But the group may have found its own fidelity to the subject matter with its aggressive earnestness. After all, isn't that how 10-year-olds usually play?