The San Francisco Symphony's performance of Leos Janacek's ``Glagolitic Mass'' on Thursday night was one of those rare concert events: not just an absorbing experience but an enveloping one. Joined by the 143-voice San Francisco Symphony Chorus and organist John Walker, the orchestra made music that was sonically drenching and massively, almost bluntingly, emotional.

Conductor Michael Tilson Thomas seemed at times to be gathering up the winds for this heaving tribute to God and nature. And that was just one segment of a uniquely imaginative program at Davies Symphony Hall that covered vast musical ground with intelligence and heart. It managed to be entertaining, too, and the house was just about full.

The program, which repeats tonight, began with intimate, ghostly violin duets by Luciano Berio, performed by members of the symphony and unflinching students from the San Francisco Symphony Youth Orchestra. This was inspiring stuff: teachers and students on equal footing, pulling off moody and often technically intimidating miniatures by a modern master.

It continued with the San Francisco premiere of Tilson Thomas' new composition ``Island Music,'' scored for two solo marimbas and a small ``percussion orchestra,'' a liquid, dream-time reverie at once relaxed and refined, much like the Balinese music that forms one of its currents of influence. This was crystal clear music, uncluttered and approachable, and driven by a mischievous, game-playing intelligence.

Finally, there was the Janacek. What a wallop it packed. What a performance by the chorus: both heavenly and thrusting. And what soloists: Young soprano Measha Brueggergosman, making her Bay Area debut, showed off a lustrous powerhouse voice that sailed through the massed sonorities of orchestra and choristers.

Janacek, who claimed to hate the institutional church, wrote his Mass in 1926, when he was 72, drawing on the Old Church Slavonic liturgy. The Czech composer made a nationalist statement by setting the ``Kyrie,'' the ``Gloria,'' all the parts of the Mass, in the old Slavic tongue which, according to scholars, possibly was notated with an alphabet known as Glagolitic.

The composer must have been a believer, because the music has a church-bells-pealing power and sanctity. But Janacek had the heart of a pantheist. He loved the woods and animal sounds, and his Mass reflects that enchantment. It's buzzingly alive. Songs move in undulating waves. Eddies of rhythm create a whirling undertow. It's a golden brew; textures somehow feel crisp and thick, glowing and guttural.

It's a work to savor, and the musicians did that; this was the orchestra's first performance of ``Glagolitic'' in a decade. The piece concludes with a mad ostinato movement for organ, played Thursday with appropriate frenzy by Walker (though Davies' pipe organ should be adjusted to literally shake the house more than it does), and a fanfare-ish finale, with rising strings desperately holding onto a reiterative three-note figure. One commentator has called this ``a marching entry into life,'' and that's what it sounded like.

What a contrast it made to Tilson Thomas' piece, which had its world premiere in 2003 in Miami Beach. ``Island Music'' is all low volume and understatement, floating and open in sound. It's music that might drift through your consciousness while you are cat-napping after one of those restorative sun-showers that happen on beaches in Bali or the Caribbean.

In fact, Tilson Thomas began formulating the work during his first trip to Bali some time ago. Playing around with wooden instruments from a local gamelan, he wrote in the program notes, he composed a ``bouncy little tune'' that became the work's kernel.

Of course, the piece grows complicated, though it doesn't sound it. ``Island Music'' works with riffs and rhythms that have the aroma of Bali, of Jamaica; it's hard to place what island you're on, because it's really Tilson Thomas's musical island that's being constructed.

According to the composer, the ``bouncy little tune'' is really the ``A'' section of a rondo, akin to the format of much of Schubert's music. Surely this is the least Schubertian piece ever inspired by Schubert.

Thursday, marimba soloists Jack Van Geem, the symphony's principal percussionist, and Nancy Zeltsman engaged in soft call-and-response, answering and completing phrases. There were gently bonging and clanging sounds -- tributes to gamelan or steel drums or the invented percussion instruments, made of sawed-in-half oxygen tanks, of the late composer Lou Harrison, to whom the piece is partly dedicated. There were occasional flashes of Steve Reich minimalism, but without the dense, obsessive layerings of rhythm.

What emerged was something sensually rigorous, a low-key work with a slight case of nerves. Gentle dance rhythms evolved, drifted away, and returned. Riffs and rhythms were sampled, steadily altered and spiced with clave or careful percussion from bongos and chimes. There was a sort of gamesmanship going on, Tilson Thomas challenging the listener to find linkages between musical materials and influences in the four-movement piece (which went on a mite too long).

It finished with a coda that, he wrote, is ``indebted to both Beethoven and James Brown.'' I heard Xavier Cugat. How interesting that these are the sounds that float through the conductor's head.

`Glagolitic Mass' by Leos Janacek, `Island Music' by Michael Tilson Thomas, `Duets for Two Violins' by Luciano Berio

San Francisco Symphony

Where Davies Symphony Hall, 201 Van Ness Avenue, San Francisco

When tonight at 8

Tickets $30 to $103, (415) 864-6000, www.sfsymphony.org