Los Angeles Master Chorale

Los Angeles Master Chorale's 50th anniversary concert was conducted by Music Director Grant Gershon. (David Johnston / September 24, 2013)

The Los Angeles Master Chorale did what organizations are expected to do when they are about to turn 50. It looked back and patted itself on the back.

In a marathon gala at Walt Disney Concert Hall on Sunday night that lasted more than three hours, the chorus sang 25 pieces with a range of dates from the Middle Ages to the other day, and in an incomprehensibly wide variety of styles and genres. Grant Gershon, the ensemble's music director since 2001, conducted. The singing was sensational, all of it, whether kitschy, quirky or spiritually transporting.

The celebration, meant to show how the Master Chorale became one of the world's great choruses, was not a birthday party but rather the beginning of the chorus' 50th season. The actual 50th anniversary is early next year, by which time the Master Chorale will be busy with its main purpose, which is to move forward and to matter. That will include a performance of Bach's Mass in B Minor followed by three concerts of contemporary works, including premieres of pieces by David Lang and Esa-Pekka Salonen.

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In fact, 50 is simply the age of a name, not a chorus. That chorus was the Roger Wagner Chorale, formed in 1946 and known throughout the '50s for its television appearances, Grammy-winning recordings, notable international tours (such as performing at Queen Elizabeth II's 1953 coronation in London) and film soundtracks. Wagner christened his chorus the Los Angeles Master Chorale in 1964 when the Dorothy Chandler Pavilion was completed and the ensemble become one of the Music Center's resident companies.

So Sunday began with Wagner, a big personality in L.A. music history who was born in France and competed on the French decathlon team at the 1936 Berlin Olympics. He created a refined multi-dimension choral sound like no other. He went in for old-timey, and he had a very wide sense of that, from old chant to old-fashioned pop. That meant bizarre contrasts. The 16th and early 17th century Spanish composer Tomás Luis da Vittoria's "Ave Mariavoices" magically floated in space. They then crashed to earth in Wagner's hokey arrangements of "Home on the Range," "Danny Boy" and "I Dream of Jeannie," suavely sung though they were.

The Kyrie from Paul Chihara's Missa Carminum Brevis, however, made sense. A Bicentennial commission from Wagner in 1976, it merges a traditional liturgical setting with folk songs ("Sally Gardens" in the Kyrie), to achieve the kind of genuine cultural commonality that ultimately became a hallmark of the chorale.

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John Currie, Wagner's successor in 1985, attempted to take the Master Chorale in new directions. Also an opera conductor, he emphasized large-scale dramatic works. A Scotsman, he introduced Scottish kitsch and kilts (bagpipers from Pasadena made a surprise appearance in Currie's honor). He lasted only five years. But he at least gave Gershon the excuse for a moving performance of Mozart's "Ave Verum Corpus."

The 1990s belonged to Paul Salamunovich, a Wagner protégé and specialist in Gregorian chant who simultaneously returned the chorale to its roots and moved it forward. One of the most lasting ways of doing that was by championing Morten Lauridsen, whose music has the rare and lasting combination of maximum sweetness with minimum sentimentality and who became a major voice of the chorale. Gershon's incomparably effervescent performance of Lauridsen's 1994 "O Magnum Mysterium" was as good an example as any of the Master Chorale's special sound. That performance also represented the progress the chorale has made under Gershon.

A protégé of Salamunovich (who he announced was too ill attend, as was Currie), Gershon set out from the start to head in just about every direction a chorus could go. He made the programming contemporary, even avant-garde, while still maintaining a foundation in early music. He has continued with, but made more sophisticated, popular programs, by bringing in jazz and world music. He moved the chorale from the pavilion to Disney Hall in 2003 and used the new hall's acoustics to significantly polish and purify the choral sound and to experiment.

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Sunday's selection from Gershon's dozen years leading the chorale was a necessarily crazy mix. He led Thomas Tallis' "Spem in Alium," a motet in 40 parts, with nine groups of singers spread through the hall. He threw in Korean music he had commissioned, as well as Rachmaninoff, Ellington and colonial music from the New World. Even so, he barely touched the surface.

But the choristers did touch a great many of Disney's surfaces when, for a finale, Gershon invited 100 alumni of the chorale to join the current members for Randall Thompson's "Alleluia." It was a blowout.

Gershon had a few helpers that included associate conductor Lesley Leighton, pianists Lisa Edwards and Shawn Kirchner (the chorale's current composer-in-residence) and percussionists Theresa Dimond, Timm Boatman and Alex Acuna. County Supervisor Mark Ridley Thomas read a proclamation of praise, not overstated.

But mainly this night was for the singers to show how amazing they have become.

mark.swed@latimes.com