Walking briskly to center stage, as he had done countless times for 18 seasons with the Atlanta Symphony Orchestra, music director Robert Spano was thinking about leading the orchestra through the tricky grooves of Michael Kurth's "Everything Lasts Forever." The audience greeted him, unexpectedly, with a raucous standing ovation.

It was January 2018. Just two days earlier Spano had announced he would leave his post at the end of the 2020-2021 season. The rare, pre-concert cheer seemed a cathartic response from an appreciative community. For a generation of ASO patrons, Spano simply is the orchestra; he's all they've ever known.

Once at the podium, Spano, a wry smile on his face, seemed to bow a little longer and a tad deeper. The conductor, musician and composer has been central to the symphony’s success for nearly two decades.

Heading into its 75th season, which opens Sept. 20 with violinist Joshua Bell, the ASO is celebrating a milestone birthday, but also reflecting on Spano's career. The fourth music director in ASO history, Spano has had a significant impact in shaping both the sound of the orchestra — he has hired roughly a third of the current ensemble — and the symphony's image, both locally and nationally. He has pushed the musicians to stay engaged and challenged by commissioning new works from young composers like Kurth, an ASO bassist, while Spano's novel collaborations with modern dance troupes and theater companies have infused old works with whimsy and imagination.

Spano arrived in Atlanta in 2000, following the departure of music director Yoel Levi and in the wake of the death of Robert Shaw, the venerated ASO music director who formed the chorus and brought the orchestra from a regional ensemble to worldwide acclaim starting in the late 1960s. Previously, Spano was steering the Brooklyn Philharmonic and keeping up a steady calendar of guest conducting and piano gigs. (He remained Brooklyn’s music director until 2004.) But he longed for a new artistic endeavor.

That undertaking took the form of a lasting partnership with the ASO and an eventual alliance with principal guest conductor Donald Runnicles. Spano can still remember when he, then music director designate, huddled together in a Delta smoker’s lounge at Atlanta Hartsfield-Jackson Airport with Runnicles and ASO President and CEO Allison Vulgamore for the first of myriad discussions about the future of the orchestra. They ended up hatching a unique collaboration among conductors that would sustain the ASO’s creative energy well into the 21st century.

“I really wanted to come to Atlanta, and I was sure it wasn’t going to happen because that’s what I wanted,” Spano, 58, said. In Atlanta, the usual role of the music director as a top-down leader was to immediately give way to an egalitarian model. “Part of it was the idea that (Donald and I) would be a team. That was such an appealing idea to me, and it was something that was even more rewarding than I could have anticipated.”

Group effort

Collaboration is in the ASO’s DNA. It is perhaps most apparent in the so-called War Room, where ASO staff can give input on programming for upcoming seasons. Seeking input from diverse voices allows the ASO to better connect with its audience, giving concerts a more communal feel, said assistant conductor Stephen Mulligan.

“Robert is really big at building consensus,” Mulligan said. “He feels that the results will be better if more people in the orchestra and in the staff are energized and motivated intrinsically to contribute.”

Within the organization, people who have worked closely with Spano point to his dazzling intellect, intense curiosity and dedication to teaching and nurturing new musicians and conductors as keys to his success. Principal clarinet Laura Ardan has known Spano since he first arrived and often has experienced the freedom he gives orchestral soloists.

“He will wait for you to have an idea, and that’s a very, very different concept than other conductors,” said Ardan, who is commissioning Spano to write a duet for clarinet and piano. “It creates a really different performing experience.”

Another significant collaborator is the ASO’s volunteer chorus, which remains one of the organization’s greatest assets. Here, Spano’s alliance with Norman Mackenzie, ASO’s director of choruses, gives contemporary audiences a direct link to the choral legacy of Robert Shaw.

“There are marvelous, marvelous orchestral conductors, who just kind of don’t know what to do in front of a large chorus when they get on the podium,” Mackenzie said. “The brilliant thing was, Robert (Spano) was great in front of the chorus.”

Within the first few years after taking the podium as music director, Spano and the ASO began commissioning and recording substantive orchestral works from composers such as Christopher Theofanidis, Jennifer Higdon, Osvaldo Golijov and Michael Gandolfi. These composers came to be known as the Atlanta School of Composers. Over the course of Spano’s tenure, he and the ASO have expanded the roster.

Kurth has become part of the second wave of the Atlanta School of Composers. The ASO has commissioned a number of his compositions and released a recording of his works earlier this year.

“I love playing modern music with him, especially when it’s mine,” Kurth said of Spano. “When we’re playing mixed meter stuff or really bombastic stuff, he just shows you with his whole body and his whole soul how the music should go.”

Spano’s creation of the Atlanta School is now a model for orchestras throughout the country looking to create more new-music programming. The ASO’s recent hire of Elena Dubinets as the chief artistic officer is a sign that this thinking will outlast Spano’s tenure. She helped commission scores of new works during her long tenure at the Seattle Symphony.

“Robert has really identified a group of composers who have some commonalities, at least aesthetically. That’s something that many orchestras have looked to as an example of a very deep and effective way to engage with living composers and their music,” said Jesse Rosen, president and CEO of the League of American Orchestras.

Highs and lows

Success for Spano’s ASO has ebbed and flowed. In 2012 and 2014, the ASO musicians found themselves locked out by management over contract disputes, and those events had a devastating and lasting impact. Ardan said that even today, the orchestra isn’t back to where it was before the first lockout. Through it all, she said, Spano stood up for his musicians in the labor dispute. Ardan and her colleagues are now under contract through 2021, thanks to early negotiations led outside the public eye by ASO executive director Jennifer Barlament, and management touts a five-year string of financial surpluses. But the past still casts a shadow.

“It’s so painful that it’s not something one forgets,” Spano said. He is still trying to reconstitute the orchestra with auditions for new musicians, and will continue to do so during his final two seasons. “The restoration is still real. But I do think we’re well past getting back on our game, so to speak, and I’m very proud of how the orchestra sounds and how they’re playing.”

Even after two decades and two lockouts, Spano relishes the relative scrappiness of the ASO.

“I’ve heard that said often in my time here that we punch above our weight. Relative to orchestras with which we are often in league, we’re operating with a shorter history, with a smaller budget, ” Spano said. “We’ve done things that other institutions have looked to and said, ‘Oh, we need to find our way of doing that.’”

The next phase, the ongoing hunt for its next artistic leader, calls for a bit of soul searching from the ASO. A search team has been formed, but there’s no hard deadline for a decision on a new music director.

“It’s an iterative process,” Barlament said of the music director search. “Things take twists and turns, and you think you know from the beginning where you’re headed and somebody pops out of nowhere and surprises you. So we’re exploring many options and thinking really hard about priorities and where we want to go in the future.”

Shaping a future

For now, Spano plans to maintain his residence in Atlanta because the community has become his community. Barlament has said Spano will return on a regular basis to conduct the symphony and chorus, but he will also serve as principal guest conductor of the Fort Worth Symphony, leading the orchestra in two concerts each season for the next three years. Beyond those plans, his calendar is open.

“My whole life I’ve juggled with playing piano and writing music and conducting and teaching,” Spano said. “My passion and interest for all those things remains, and so how I might balance my life differently now is a very interesting question.”

Spano’s stamp on the orchestra, and his role in the creative partnership that began with Vulgamore and Runnicles, will outlast his stay in front of the orchestra.

“Robert’s legacy is his effusive, charismatic, persuasive personality, his passion for contemporary music and his passion for mentoring young conductors,” Runnicles said. “He has expanded the orchestra’s and the chorus’s experience of music, and with that he has expanded the experience for the audience.”

This year’s 75th season is a birthday party for the orchestra, but it’s just the start of a continued celebration for Spano.

Centennial Olympic Park. Assistant conductor Stephen Mulligan brings the orchestra and soprano Jennifer Cherest to Centennial Olympic Park for a night of classics. Sept. 25. Free. Centennial Olympic Park, 265 Park Avenue West, Atlanta.

Donald Runnicles. Runnicles makes his first appearance of the season with mezzo-soprano Kelley O'Connor to perform Korngold's "Lieder des Abschieds." Bruckner's Symphony No. 4 and orchestral excerpts of Wagner round out the program. Oct. 31, Nov. 2. $29-$98.

Beethoven at 250. In celebration of Beethoven's 250th anniversary, ASO concertmaster David Coucheron will perform the composer's violin concerto in a program that also includes "Two Organa" by Oliver Knussen. Jan. 16-19. $33-$109.

'Tristan und Isolde.' Over three nights, Spano will lead the ASO, ASO chorus and a guest cast of singers in Richard Wagner's "Tristan und Isolde." One act of the three-act opera will be performed each night. June 11-14. $22-$98.

Unless otherwise noted, performances take place at Symphony Hall, 1280 Peachtree St., Atlanta. 404-733-5000, www.atlantasymphony.org.