Different paths to a rare beauty

It’s a fairly common practice for a single ensemble to cook up a special project as a gift to itself for a round-numbered anniversary.

It’s something else when two ensembles mark such milestones that way jointly, as the Shanghai Quartet (25 years running) and San Francisco’s all-male vocal group Chanticleer (30 years) are presently doing.

Their project is a striking new co-commissioned piece by Chinese American composer Chen Yi, “From the Path of Beauty,” unveiled March 13 in San Francisco and reprised Tuesday night at the Irvine Barclay Theatre.

The composer calls her 37 1/2 -minute, seven-movement evocation of ancient Chinese arts “a song cycle for mixed voices and string quartet” -- a laconic description that hardly begins to define the piece. For one thing, there are no texts, just nonsense syllables based on Chinese folk music. Sometimes there are no voices. Two of the movements involve the quartet alone -- and these sections, plus a transcription of the a cappella opening movement, can be performed separately by quartets.

The first two movements are the most fascinating and original. In the opening movement, Chanticleer’s unique creamy vocal blend is exploited to the max as the voices separate, fall in glissandi or form dissonant clusters firmly anchored in the bass. Shanghai joins the show in the second movement with whistling harmonics way up on the strings as the voices continue their slippery ways. Someone in the audience Tuesday was moved to shout, “Splendid!” -- and I can’t blame him a bit.

Eventually, though, the piece gravitates toward more conventional Western textures and composers. The fifth movement’s melodic bent reminded me, perhaps incongruously, of Vaughan Williams in a folkish mode, and Bartok seems to kick up his heels in the wild, thrumming concluding romp (subtitled “The Village Band”).

The rest of the program cleverly tried to stretch the interconnections further as Chanticleer seamlessly explored three of Ligeti’s formative, pre-1956 a cappella pieces (“Papaine,” “Idegon Foldon” and “Magany”) and a stunning Ligeti-inspired transcription of Ravel’s “Soupir.” Then the Shanghai returned with Ravel’s String Quartet -- ravishingly polished, with the slightly pentatonic flavor of the slow movement linking it to three Chinese folk songs that both groups offered as encores.