As global as classical music has become, regional differences are often still audible in performance, revealing musicians’ origins as surely as an accent.

At Saturday’s opening of the concert season for the Honolulu Chamber Music Series, the Zemlinsky Quartet of the Czech Republic presented an idiomatic and insightful performance of Leos Janacek’s Quartet No. 2, the centerpiece of the group’s program.

As with an accent, an idiomatic musical style does not lend itself to being described in print, but it often elicits an "ah-ha!" reaction from listeners; passages and structure seem to flow more clearly and to make more sense.

The Zemlinsky Quartet displayed a special affinity for Janacek’s quartet, moving smoothly between lyrical, folklike and furious sections, focusing on each moment while keeping the whole in sight.

Janacek described the piece as "composed in fire," a description that may have had less to do with musical content than with his sexual passion: The piece is subtitled "Intimate Letters" and depicts his infatuation with a woman less than half his age. Nonetheless, it is not the story that holds the piece together so much as how the musical structure is conveyed.

The Zemlinsky Quartet, named after the Austrian composer, conductor and teacher Alexander Zemlinsky (1871-1942), has been performing and winning awards since its inception in 1994.

Over the years, the group has developed a distinctive blended style that sounds less like a conversational four-voice quartet than a single, four-part voice. The musicians — Frantisek Soucek and Petr Strizek (violins), Petr Holman (viola), and Vladimir Fortin (cello) — present a musically united front, each playing intently toward a shared vision, continually adjusting to maintain cohesion and at times even breathing together.

The program at the Academy of Arts’ Doris Duke Theatre opened with Haydn’s Quartet Op. 76 No. 3, nicknamed "The Emperor" after the "Kaiser Hymn" theme from the second movement, which became Austria’s national anthem.

The quartet had an unsteady opening that settled in by the development section and played the repeats straight rather than as an opportunity to elaborate, but they captured beautifully the clear, good-natured Austrian "Gemuetlichkeit" that so permeates Haydn’s music.

Half the fun of listening to Haydn is his high-spirited style. He has possibly the finest sense of rhythm of any composer before jazz came along — syncopations that shift across beats, surprise turns, sudden stops — and an irascible sense of humor, with melodies that get "lost," harmonic "dead ends" that the performers have to back out of, and harmonies that twist into a convoluted knot, only to unravel inexplicably into a final cadence.

The famous second movement is a theme and variations: The Kaiser Hymn is presented in its entirety, unchanged, by each of the musicians, beginning and ending with first violin, with only the accompaniment changing. Rather than allowing the melody to recede into the background and focus to shift to the variations, the Zemlinsky Quartet chose to foreground the melody each time so that by the fifth time through, everyone was humming along, at least mentally.

The quartet closed the program with Schumann’s Op. 41, No. 1, a work that highlights Schumann’s fondness for experimenting with structure and tonal relationships. Of particular note were the long, arching melody of the Adagio and the brilliant Scherzo, which began tentatively, then took off like wildfire, ending in a dramatic flourish.

In response to a standing ovation, the quartet gave as an encore an exuberant reading of the finale from Dvorak’s "American" quartet, which was on the program when the Zemlinsky Quartet last performed in Honolulu two seasons ago.

Next in the Honolulu Chamber Music Series is a Nov. 6 performance by the Los Angeles Guitar Quartet. Tickets are available at the Honolulu Academy of Arts and online at www.honoluluacademy.org. For information, call 532-8700.