MUSIC REVIEW : Athenaeum Ignores Caution and XTET Delivers : Modern Music: New chamber season at La Jolla facility begins on a high note with contemporary American music, usually shunned during slow economic times.

When the economy slumps, conventional wisdom prescribes a strictdiet of cautious, conventional programming. But the La Jolla Athenaeum ignored this cowering bromide and opened its new chamber music season Sunday evening with a program of contemporary American music by the Los Angeles-based XTET.

Although the cozy, modest arts and music library seats but 100, a full house greeted Sunday’s visiting musicians. XTET returned the compliment with well-prepared, stylish performances uncluttered by the worshipful affectations that sometimes accompany this genre. Genial but not overly talky introductions from the performers eased the listeners down unfamiliar paths.

At the heart of Sunday’s program was Lukas Foss’ 1961 “Time Cycle” for soprano and four instruments, sung with amazing precision and conviction by soprano Daisietta Kim. “Time Cycle” gracefully exploits expressionistic vocabulary--the spare instrumental pointillism, the disjointed, angular melodies--without sounding like re-composed Schoenberg. The ensemble, which also included clarinetist David Ocker, cellist Roger Lebow, percussionist David Johnson and pianist Vicki Ray, deftly recreated the work’s delicately acrobatic structures and painted the mood of each of the four poems with appropriate hues, from W. H. Auden’s austere sermonizing about time to Franz Kafka’s neurotic imaginings.

Kim’s pure, focused tone, nimble legato and ever intelligible words added to the delight as well as the understanding of Foss’ opus. She brought equal acuity to a pair of early John Cage songs, “The Wonderful Widow of Eighteen Springs” and “forever and sunsmell.” In “Wonderful Widow” she suspended a mesmerizing chant over a percussion drone tapped on a closed piano, meekly executed by Ray. In “forever and sunsmell,” with its drum and Chinese gong accompaniment that invoked some ancient Oriental court procession, Kim conjured a magical incantation.

Although David Rosenboom’s “Seduction of Sapentia” began inauspiciously as just another minimalist etude, its pounding chordal motif gave way to a highly virtuosic, jazzy vibraphone solo played with considerable elan by Johnson, who subdued its complex rhythms with technique to spare.

Ocker’s own 1977 composition “Backward, Looking, Forward,” for clarinet, piano and vibraphone, seemed unduly precious and self-conscious. Its opening movement offered a languorous clarinet melody with modest piano accompaniment, but the three ensuing movements academically dissected the compositional ideas into permutations of progressively smaller scope.

As the concert’s prelude, Leonard Bernstein’s 1941 neoclassical Clarinet Sonata proved a winning choice. If only Ocker had chosen the confident, flowing approach of his accompanist, Ray, rather than his own stiff, earnest student demeanor.