Choral Arts offers a fresh look at some rarer Rachmaninoff

Never wanting for artistic status, Rachmaninoff's

Vespers

(a.k.a.

All Night Vigil

) showed the Russian composer-pianist fusing his taste for symphonic grandeur with lesser-known talents for opera and art song - while tapping into the Russian Orthodox liturgy, the deepest vein of his national identity.

Yet the music's cultural specificity is exactly what made the Choral Arts Philadelphia's brave, often-accomplished Saturday performance a blue-moon event. Only after years of more open cultural exchange and a greater Russian presence in the United States has the piece been truly in reach of American choirs.

Mstislav Rostropovich and Robert Shaw both recorded the work with American singers in decades past. But only with a certain assimilation with the language can the words begin to truly color the vocal timbre of any given group. One heard that in the Choral Arts performance under Matthew Glandorf at the Cathedral Basilica of SS. Peter and Paul, but more as a solid starting point than a moment of arrival.

Composed in 1915 as the life Rachmaninoff knew in imperial Russia was ending, the Vespers emerged as even more of an ingenious hybrid on Saturday than one could appreciate from years of hearing Russian-made recordings. Though the performance floated in a proper ethereal haze (enhanced by the basilica's warm acoustics), one became more aware of non-liturgical influences (folk song, for one) as well as a heightened rhetorical profile.

More traditional church music assumes the sacred texts need little help from the music. But Rachmaninoff's dramatist side is heard here, not going to operatic lengths but still projecting a deeply personal sense of meaning, as well as responding to the meter of the words with his own kind of phrase organization. Rachmaninoff honored the historic formalities of the medium while also giving them a cosmopolitan transformation. That's why the piece has long promised to achieve universal appeal, well beyond its liturgical function.

The challenges for the Choral Arts singers (scaled at 39 voices) did not stop at encompassing the language. In this unaccompanied work, the composer often anchored passages with a long-sustained note or pedal tone. The inevitable vocal tiring was audible only in the last few movements of this 60-minute, intermissionless work.

The performance had a welcome 21st-century American accent: The music's not-always-apparent modernity has rarely been more apparent. The stretching and genteel clashing of tonalities in the music revealed parallels with current composers such as Gabriel Jackson and Eric Whitacre. Such parallels also suggested future possibilities should Choral Arts continue pursuing Russian repertoire: The goal is to inhabit the idiom so completely that the group speaks though the music as readily as it does with its current, homegrown composers. And this performance was at least halfway there.