Valerie Coleman’s stirring ‘Umoja’ is a Philadelphia Orchestra milestone: The first classical work by a living African American woman that they have performed.

The Philadelphia Orchestra’s program note Thursday night said the concert marked the first time the orchestra had played a work by Valerie Coleman, and that her piece was an orchestra commission and world premiere.

The greater significance behind the debut of Coleman’s Umoja, Anthem for Unity, though, is this: It was the first time the Philadelphia Orchestra had ever performed a classical work by a living African American female composer. And so the concert raised a two-part question fraught with complexity and paradox. What took them so long, and why does it matter?

Let’s start off by calling Umoja, Anthem for Unity exactly what it is apart from the question of who wrote it. It’s a terrific work. The piece — umoja means unity in Swahili — arcs from serene peace to racing tension before emerging in sunlit joy. That’s a lot in 10 or so minutes. Coleman is not primarily an orchestral composer (she was best known for years as the flutist in Imani Winds), but her new work is a powerhouse of emotional directness and bold orchestration.

As for the who behind the piece, it does matter. For all kinds of reasons.

An orchestra spokesperson said the group believes this is the first time it has commissioned a new work from a female African American composer. That it took it 120 years of actively commissioning composers before landing on this demographic says a lot about how little the orchestra has noticed the city it has lived in all this time. Coleman’s identity is an important factor to many, but especially to children all over who may never have thought this world was open to them — as composers and listeners.

The messaging is more delicate than many realize. My Asian American daughter, no stranger to concert halls, was 5 or 6 when we saw an Asian American girl playing piano at one of the orchestra’s family concerts. She whispered to me that it had never occurred to her that such a thing was possible.

Yannick Nézet-Séguin led the Coleman premiere. On Facebook not long ago, orchestra piccolo player Erica Peel posted a shot of a page from the score. “Erica solo,” it says at bar 146. And in fact, Umoja has a concerto grosso feel at times. There’s a tasty bass clarinet solo, a spritely breakout moment for oboe played by Philippe Tondre, guesting in the principal chair for the evening, and other section solos.

The piece has its origins in a 1997 version for women’s choir and it has been adapted for other forces. But here it seems to have arrived at its inevitable state, where texture and instrumental contrast take on emotional hues. It opens with the promise of spring, like a beginning. Let’s hope it is. A full-length orchestral piece from Coleman next would be welcome.

As it was, the big work on this program, the first subscription concert of the orchestra’s 2019-20 season, was Dvorak’s Symphony No. 9 in E Minor, “From the New World.” There is no bad reason to program the piece, but it is played a lot, and it’s not entirely clear to me what the impetus was here. (The orchestra last performed it in April 2017.) The best reason would have been if Nézet-Séguin had had some urgent interpretive idea to communicate. But although he certainly knew how to crank up the work’s final climax, his take was not highly individualistic.

The best thing about it: the lovely patina of Elizabeth Starr Masoudnia’s English horn solos.

Coleman’s Umoja and Dvorak’s symphony both call on folk melody, an inspiration obvious in much of Bartok’s Piano Concerto No. 3, for which Hélène Grimaud was the soloist. The pianist dazzled, as she does so well, in the outer two movements. But it was her tender work and the matched sound of the ensemble that made me want to hear the second movement again.

One enters this music as if it were a peaceful forest, quietly and with reverence. The movement is marked “adagio religioso,” and it made me think back to the Fresh Air chat last season in which Nézet-Séguin said he had become “increasingly more spiritual than religious.” It may be a matter of semantics, but if the the hushed, untroubled atmosphere in the second movement of the Bartok was a manifestation of his beliefs, the distinction really didn’t matter.

CLASSICAL REVIEW

Philadelphia Orchestra

The program repeats 8 p.m. Saturday and 2 p.m. Sunday at Verizon Hall in the Kimmel Center, 300 S. Broad St.

Tickets: $39-$179.

Information: 215-893-1999 or philorch.org.