Live: The Philharmonia Orchestra, conducted by Christoph von Dohnanyi

The average age of the four conductors named on the masthead of the Philharmonia Orchestra, which made its Walt Disney Concert Hall debut Tuesday night, is 81. And four months. The 78-year-old Christoph von Dohnányi, who is leading his final tour with the London orchestra, is principal conductor. In the fall, he will become honorary conductor for life, and Esa-Pekka Salonen, who will be 50 at the time, will take over.

This will be a fascinating generational shift in the life of a relatively young orchestra with a history of associations with old-school maestros. Founded at the end of World War II as a recording ensemble, it hooked up early with Toscanini, Furtwängler and particularly Herbert von Karajan. It has flirted with audacious youth: Riccardo Muti and Giuseppe Sinopoli led it early in their careers. Salonen was principal guest conductor from 1985 to 1994. But the orchestra is still at least somewhat identified with the formidable Otto Klemperer, who served as music director from 1959 to 1972. Klemperer was music director of the Los Angeles Philharmonic for most of the 1930s. Now Salonen moves in the opposite direction.

Meanwhile, the Philharmonia is, at the moment, one weighty ensemble. Besides Dohnányi, the band boasts associations with Kurt Sanderling (conductor emeritus), Charles Mackerras (principal guest conductor) and Vladimir Ashkenazy (conductor laureate).

Dohnányi's tour is all meat and potatoes. For Tuesday's concert, he led Mendelssohn's Fourth ("Italian") Symphony and Mahler's First. Tonight at the Orange County Performing Artscenter, he is scheduled to repeat Wednesday's Disney program: Beethoven's "Egmont" Overture, Schumann's First Symphony and Beethoven's Fifth. If Tuesday was any indication, anyone planning to attend tonight's concert shouldn't expect an Elgar encore, or any encore. And no one should attend in a mood for frivolity. These concerts are serious business.

During his long career, and particularly during his tenure as music director of the Cleveland Orchestra in the '80s and '90s, Dohnányi admirably championed new and difficult music, American as well as European. These days, though, he is seen as one of the last of the great traditionalists. When the L.A. Philharmonic is looking for that Old World feeling, it brings in Dohnányi, as it did for a Brahms symphony cycle last season.

What this conductor offers most of all is a sense of security. Mendelssohn's "Italian" wasn't exactly Latin. The tempos may have been on the quick side, but Dohnányi's Italy is a land of burnished monuments that have been around for a long time. He likes a thick, molded sound, something that can give the impression that things haven't changed much for centuries. When last in L.A., he experimented by having the risers removed, seating the Philharmonic players all on one level to get a better orchestral blend. With the Philharmonia on Tuesday, he let the risers stay. Still, no section stood out, except on a few occasions when the ensemble playing wasn't precise -- strings, winds and brass all had their minor slip-ups. But the main impression was of purposeful playing, thick textures and, in the slow movement, a pleasing glow.

The Mahler First is not by a long shot the heaviest of the composer's symphonies, but Dohnányi conducts as if he bears the suffering of the world on his shoulders. Mahler had nature on his mind. Dawn breaks at the start. Peasants dance. A round to "Frère Jacques" becomes a woeful dirge. A storm brews. The symphony ends in wonderful triumph.

Everything in Dohnányi's performance got extra oomph. The high harmonics at the beginning were curiously ominous. The basses and loud brass grounded the symphony so effectively that they might have been glued to the stage. I missed any sense of play, of adventure and fantasy, in Dohnányi's approach. But if this was the symphony as sermon, the oratory was fiery, the logic irrefutable, and you simply had to pay attention.

One can fight Dohnányi's stern approach. I tried. But the players clearly revere this conductor. And in the end, when the brass stood and played too loud for the hall, when the clotted strings and winds became a sonic army, when Dohnányi's sense of mission produced a startling climax, resistance seemed futile. Something important was said, and hearing it proved very satisfying.

mark.swed@latimes.com