Levine, BSO open at Tanglewood by going out on a limb

Boston Symphony Orchestra music director James Levine, who champions Elliott Carter and Charles Wuorinen when not conducting at the Metropolitan Opera, courageously opened the Tanglewood concert season last weekend with Berlioz’s seldom-heard epic opera “Les Troyens.” The five-act, five-hour setting of Virgil’s Aeneid spanned the Saturday and Sunday concerts, and those few who sat it out marveled at its pageantry and beauty.

There is a rationale for splitting it: certainly Berlioz never heard it any other way. His always-massive spectacular vision, with gods, ghosts, kings, heroes, monsters, slaves and more, rivals that of Wagner, his contemporary. To Berlioz’s chagrin, Wagner’s operas were (and are) regularly staged, while Berlioz seemed to attract obstacles.

In truth, it’s hard to stage anything at all by Berlioz with the majesty and supernatural fantasy he had in mind. Even his Requiem has brass, percussion and choruses spilling off the stage. An accurate staging of a stupendous Berlioz work — were it possible — would make Mahler’s symphonies look puny.

Composed after “Symphonie Fantastique” and “The Damnation of Faust,” “Les Troyens” has similar fragments, and some famous moments, including Royal Hunt and Storm — an interlude cut from the first performances because it was impossible to stage — and the rousing Trojan March, with offstage band.

The opera’s two main sections have different major roles. The Trojan prophetess Cassandra, whose curse is that no one will believe her, leads the defeated Trojan women in committing suicide at the end of Act II, the first concert’s finishing point, but appears only briefly as a ghost in the second section. Aeneas, who mistakes the soldier-filled wooden horse for a gift to the Trojans, is a small tenor role that comes into its own opposite his lover Dido, Queen of Carthage, who reigns over Part II.

Exciting infusion

Just as Levine has turned the Met Orchestra into a performing symphonic entity, he is now infusing opera into the Boston Symphony’s repertory, with exciting results. He is known for full-bodied brass in Wagner, and he showed those skills in Berlioz, swiveling in his podium chair in the Koussevitzky Shed.

The emerging plan seems to be that a staged production at the Met (the institution he directs in his spare time) has a subsequent concert performance in Boston with similar cast, and then in Tanglewood, possibly followed by one in Carnegie Hall.

Supertitles served not only for the translated French text but for times when the orchestra carried the action forward or to introduce wrestlers, farmers or builders. The sacking of Troy is narrated by Panthus (Clayton Brainerd was effective) and orchestra; later, there are luminous chords as Troy is prophesied to become “more powerful.”

Levine’s inviting program note preceded a synopsis from Opera News plus a background essay by Berlioz edition editor Hugh Macdonald. With the credits, it was 25 pages. (Good luck to listeners arriving at the last minute expecting to fill in on background — they had to take the booklet home to prepare for the second concert.)

Strong pairing

This opera must have a strong, passionate Cassandra. Anna Caterina Antonacci, a pure and persuasive soprano/mezzo, paired well with smoothly reassuring Dwayne Croft as Chorebus, her short-lived fiancé who doesn’t know enough to get out of town when she warns him.

Anne Sofie von Otter, known at the Met for trouser roles, was a charming, delicate Dido, Queen of Carthage, taking on the role the late Lorraine Hunt Lieberson had created with regal sweetness at the Met’s production, which was the highlight of its 2003 season. The American tenor Marcus Haddock began the first part indifferently but rose to his role as the hero who must reject Dido to sail off to his destiny as Rome’s founder.

Soloists who in opera would be singing from memory seemed to need scores, while the Tanglewood Festival Chorus rolled its hefty, sonorous parts from memory — expressive, nuanced business as usual.

Attendance figures are no longer given, but Saturday’s Shed seating was a little loose, even after local residents were admitted free for the orchestra’s annual Berkshire Night. Sunday’s looked like a new low, with the rear sections and lawn nearly empty. Salute Levine’s bold risk, and cross your fingers that it pays off.