By Pierre Ruhe

For the AJC

When the Atlanta Symphony Orchestra performs world premieres by its so-called “Atlanta school of composers,” the audience’s reactions are often as interesting as the works themselves.

Conductor Robert Spano and the orchestra commissioned new music from Jennifer Higdon (who lives in Philadelphia) and Michael Gandolfi (from Boston) and played them side by side Thursday, finishing the evening with Mozart’s Symphony No. 39.

Over recent years, Higdon and Gandolfi (and a couple of other composers) have enjoyed a regular presence in Symphony Hall, including commissions, well-rehearsed performances and recordings of their music.

This is a rewarding turn of events for Atlanta’s musical health because, for decades, orchestras have made a cult of the conductor and promoted virtuoso violin or piano soloists as the stars of the season. Living composers, for a variety of reasons -- including a widespread disconnect from mainstream audiences -- were excluded from the marquee.

But Higdon’s “On a Wire” -- showy, exuberant, beautifully crafted -- aroused so many of the audience’s hot spots across its 22 minutes that the crowd was prepared to cheer before it was over. At the climactic rush and the thwack of the bass drum at the end, the audience erupted, hollered, stood, smiled, laughed with communal euphoria and -- this is key -- gave the petite Higdon, when she walked to center stage, the loudest and lustiest ovation of all.

Whether or not Higdon's and Gandolfi’s works prove durable, they get huge credit today for elbowing themselves, and their species, back to prominence.

“On a Wire” is an unusual concerto, scored for orchestra and the brilliant new-music sextet called Eighth Blackbird. Each Blackbird -- they played piano, violin/viola, percussion, flute, clarinet and cello -- had brief solos and sang as a unit. At several transition points they all gathered around the open piano and bowed or plucked the strings, giving the concerto an eerie sound element and strong visual component.

The concerto is pure Higdon, with jaunty rhythms that evoke Copland’s Americana at the beginning and end, contrasted in the middle by a tender, fragrant lyricism. Marimba flutters sounded like a breeze passing through a bamboo forest.

Many of Higdon’s fans are waiting for her to cross an artistic threshold and turn out a masterpiece. With emotions kept in reserve, “On a Wire” isn’t there yet.

Gandolfi’s 25-minute “Q.E.D.: Engaging Richard Feynman” was fun, mild and slight. It’s a quirky homage to the eccentric physicist, a Nobel Prize winner who has become a pop icon.

This is the composer’s first work for chorus, and he’s taking baby steps. Much of his choral writing sounds like choral recitative, with one syllable per note, and it’s set in a way that the words were not always intelligible. Gandolfi’s orchestra channels John Williams and Copland, and parts of “Q.E.D.” sounded like “Rodeo” relocated to Walden Pond.

And the audience loved it.

Pierre Ruhe is classical music critic of www.ArtsCriticATL.com.

Concert review

World premieres by Jennifer Higdon and Michael Gandolfi. Atlanta Symphony Orchestra. 8 p.m. Saturday, Symphony Hall, 1280 Peachtree St. N.E., 404-733-5000, www.atlantasymphony.org