LOS ANGELES — The ever-restless Los Angeles Philharmonic, possibly the most progressive and news-making arts institution anywhere, surprisingly began 2019 exactly as it ended 2018: suffused in tradition. Over the weekend, Zubin Mehta, long one of the world’s most famous conductors, finished a cycle of Brahms’ four symphonies and four concertos, which he had begun at Walt Disney Concert Hall at the end of December.

Aimez-vous Brahms? Aimez-vous Zubin?

Maybe you do, maybe you don’t. But Francoise Sagan’s romantic novel “Aimez-vous Brahms?” was a best-seller in 1959. Three years later, a 26-year-old Mehta became the L.A. Phil music director. He’s been in the limelight nearly 60 years. What more is there to be said about him? Or, for that matter, about Brahms, whose symphonies and concertos have been played to death?

It so happens, plenty. At Mehta’s first Brahms concert last month, it felt like time to rethink that standard Mehta wisdom of an imperious conductor strong on bravura and drama, less heralded for depth. After the full cycle, there is no question.

At the concert Thursday night, there was a ceremony to name Mehta the L.A. Phil conductor emeritus. In his 16 years as music director, he basically created a new orchestra, appointing 86 musicians. He moved it into the Dorothy Chandler Pavilion. He gave it a bold new sound that symbolized L.A.

But the 82-year-old Mehta who accepted the honor was not the magisterial figure we have known all these decades. A bout with cancer and recent hip surgery have left him needing assistance onstage.

“It all started here,” he said to the audience. He had been young and inexperienced and learned much of the repertory working with musicians who had played under the greats. “With their experience and my supposed humility, we were a good team.” He then broke into tears, something hard to imagine Mehta ever having done onstage.

But he continued to reminisce, rambling a bit. He then began Brahms’ Third Symphony somewhat unsteadily. There was a bit of rambling here as well. But I found the performance downright revelatory.

As a young critic, I had called Mehta’s performance of Beethoven’s “Eroica” Symphony formless. An editor objected: I might protest the form, but everything has form. Still, Mehta did not appear to have been thinking structurally, and I sought the essence of music in its hidden, abstract and complex building blocks.

I’ve learned over the years to care more about experience than structure. Mehta still commands, no question. But the humility is no longer supposed. His connection with the music feels far more authentic.

It’s clear, moreover, that he’s always thought about music in ways that go beyond form, though that was hard to appreciate under all the bravura. Maybe this has something to do with Mehta having grown up in India. On some level Mehta brings an illuminating Indian sensibility to Western music.

That sensibility is to treat music as something that flows like a river, as does a raga rather than, say, a frozen symphonic edifice composed of harmonic building blocks. As a conductor, Mehta has always known exactly where he was going. But it was the journey rather than the whole that characterized his performance. And especially when it comes to Brahms, whose orchestral works are formally old-school with harmonies heavy as a German winter meal. But Schoenberg saw him as a progressive, because complexity opens a world of ambiguity.

The Third Symphony is the most ambiguous. Brahms pretends he’s as rock-solid as ever, with a forceful opening. Key structures, however, are uncertain. Gorgeous melodies come out of nowhere. Brahms gets carried away with melodic invention. Rapture is lifelike; it comes when you least expect it. A conductor’s job is to make sense of it all.

Mehta, though, followed Brahms and he followed his own bliss. There was never doubt that every note is embedded in his being. The playing could be a little sloppy. It could also be downright brilliant, filling all the senses.

Of the four symphonies, the Third was thus the standout. As far as the concertos were concerned, Mehta proved a mensch, putting his soloists first. Violinist Pinchas Zukerman was slow to warm up Thursday in the Violin Concerto, with nuance coming more easily than tone quality. He was joined by the impressive cellist Amanda Forsyth on Saturday for a dramatic reading of the Double Concerto, which proceeded the Fourth Symphony.

Gustavo Dudamel, in a statement about Mehta, wrote that his “soul permeates the sound of the orchestra.” In these concerts, Mehta’s sound was unmistakable, but it was his soul that came across most of all.