If you were smart enough Thursday night to get yourself to the Philadelphia Orchestra's performance of the Ginastera Harp Concerto in Verizon Hall, pat yourself on the back. It's rare enough to encounter any work by the wonderfully inventive 20th-century Argentine master. The Harp Concerto was given its world premiere by this orchestra more than a half-century ago and has returned only one other time, in 1990.

The orchestral repertoire is like that: so vast that someone and something is always getting neglected. This piece, though, has the feeling of resurfacing at just the right time. For one thing, we don't hear enough from Elizabeth Hainen, the orchestra's very fine principal harpist who performed the Ginastera Thursday (plus Friday afternoon and Saturday night).

For another, the concerto is one of those mid-century modern works to whose musical language the world has caught up. It is startling in its freshness. Ginastera still sounds like no one else.

Harp geeks will find plenty to scrutinize: luminous harp harmonics, the rhythmic knocking on the instrument's soundboard, and the question generally of how idiomatic the work is — that is, whether it really heightens the instrument's strengths and special qualities.

Philadelphia Orchestra principal harpist Elizabeth Hainen performed the Ginastera “Harp Concerto” Thursday night in Verizon Hall.
The Philadelphia Orchestra
Philadelphia Orchestra principal harpist Elizabeth Hainen performed the Ginastera “Harp Concerto” Thursday night in Verizon Hall.

Hainen expanded the vocabulary of sounds by using two harps — her usual instrument for most of the piece, and an electroacoustic one amplified for the last section of the third movement, where the competition with the ensemble is fierce (both were Lyon & Healy). Most of the time, with a fine ear for balance from conductor Miguel Harth-Bedoya, she easily held her own.

But the greater value of the music lies beyond its harp-showcase role. It is a deeply emotional work. The first movement has a persistently suspenseful main motif, and the second is full of shadow; the nocturnal mood is so spare (is there a creepier use of celesta anywhere?) that it sounds like you finally got home safe when the strings enter.

The Ginastera was part of a programming thread billed by the orchestra as "South American Sounds." We got there by way of Cuba. In Gershwin's Cuban Overture, the quiet middle section and transition back to the opening material were led stylishly and with great expressivity by Harth-Bedoya, the Fort Worth Symphony Orchestra music director and Curtis Institute graduate (who will also be reading through rehearsals with his old school orchestra while he's in town).

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Also on the program: a stirring first Philadelphia Orchestra performance of the Piazzolla Tangazo, with its somber string opening and recurring horn solos, played with an incredibly rich soulfulness by Jeffrey Lang. It's a particularly taxing part on an infamously treacherous instrument, and Lang nailed it throughout — not just not missing notes, but also fully exploiting the heroic character of this music.

Miguel Harth-Bedoya leading the Curtis Institute of Music orchestra in a 2017 Verizon Hall concert.
David DeBalko/Curtis Institute of Music
Miguel Harth-Bedoya leading the Curtis Institute of Music orchestra in a 2017 Verizon Hall concert.

Harth-Bedoya, too, pulled off a feat, ending the concert with a piece of contemporary music: Perú negro (2012) by Jimmy López. Commissioned for the centennial of the Fort Worth Symphony, the work is a gorgeous blend of Afro-Peruvian-inspired material and flickers of driving, witchy Liszt-Berlioz chromaticism. It reaches an explosive climax, collapses, and stirs back to life in a sweeping, more contemporary-sounding sequence. There's a stacking of pitches not far from the end that recalls other moments in the concert — oddly, the ending of the Gershwin.

It's a wild piece, and, with a debt to Harth-Bedoya's sensitive and wise ear for drama, wild here fell beautifully on the orchestra.

Additional performance: Saturday at Verizon Hall, Broad and Spruce Sts. Tickets are $10-$153. www.philorch.org, 215-893-1999.