The great and grand Brahms Piano Concerto No. 2 that dominated the Philadelphia Orchestra’s Thursday concert at Verizon Hall embodies the King Lear dilemma: By the time pianists can truly fathom the piece, can they still sustain its 50 minutes of pianistic heroism?

Now approaching his 70th birthday, Emanuel Ax is in that zone where he, indeed, delivers the complete experience, or at least he was on Thursday, maybe not quite to the extent of his for-the-ages Boston Symphony Orchestra radio broadcast last spring but still much more satisfying than, say, the equally eminent 74-year-old Nelson Freire, who recently rushed through the concerto at Carnegie Hall with the Mariinsky Orchestra.

In contrast, the Ax temperament has always been expansive — with a crystalline sonority that has long made him an immediately identifiable keyboard personality. Such qualities were heard Thursday but with an extra sense of rightness that told you this is the way the music has to be.

Of course, every great pianist has a personal version of rightness. But Ax is particularly convincing in the details.

Brahms' repeating sequences of phrases can be laborious, but they became essential blocks in the musical edifice. Nanosecond hesitations, often near the end of a phrase, revealed new meaning in passages you’ve heard many times.

And does anybody fluff a phrase more poetically than Emanuel Ax? It’s going to happen at any age, but with his long-cultivated overall concept of this piece, it matters much less.

For his part, music director Yannick Nezet-Seguin had the orchestra playing like a well-seasoned chamber music ensemble, with principal players making highly personal statements in their incidental solos, particularly cellist Hai-Ye Ni in the third movement. Any number of other moments had sonorities blended to give needed inner muscle to orchestral passages.

Many of the same attributes were heard in Dvorak’s Symphony No. 7, whose warm-bath orchestration showcased the Philadelphia sound but in the final movement took a leaner turn — this is freedom-fighter music, written during the emergence of Czech national identity — allowing all layers of the orchestration to be heard with equal intensity.

Elsewhere in the piece, Dvorak just wouldn’t say goodbye to his musical ideas, stretching them out with nostalgic longing with one mutation after another. Nezet-Seguin made you share that longing with flexible pacing and thoughtfully molded phrases that had you following the composer’s thoughts more exactly than usual.

The concert’s wild card was an 11-minute orchestral work, Perspectives, by Montreal composer Stacey Brown, whose considerable promise is apparent on her SoundCloud.com composer page with electronically influenced sonorities in her song cycle The Horror of Being Forgotten.

Similar sounds are heard in Perspectives, which depicts her musical reaction to looking at a Michel Longtin sculpture from different viewpoints. I heard an intuitively built tone poem that didn’t require explanation and moved from one intensely colored episode to another, sometimes with Sibelius-tinged loneliness and the liberated harmonies of Ligeti.

The Philadelphia Orchestra didn’t give the most convincing performance, and that’s what is needed to take the full measure of the piece.

The program is repeated Friday, Nov. 30, and Saturday, Dec. 1, at the Kimmel Center. Tickets: $44-$183. Information: 215-893-1999 or philorch.org.