It remained largely a choral organization through its performances at the 1904 World's Fair under Alfred Ernst when it expanded to a 200-member chorus and an orchestra of 55.

The St. Louis Symphony has recorded for the Columbia, RCA Victor, Red Seal, Telarc, Vox/Turnabout, Angel EMI, and Nonesuch labels.

During his tenure, the orchestra made many recordings for the EMI and RCA Victor labels, and toured to Europe and the Far East, as well as concerts at Carnegie Hall.

[2] In 2000, the executive director and President of the SLSO at the time, Don Roth, had secured a US$40 million challenge grant from the Taylor family (owners of privately held Enterprise Rent-A-Car) to help the organization's money situation.

Both parties then reached a mutual agreement under which they agreed to refer to the eight-week period as a "Work Stoppage" and the "Vote of No Confidence" was rescinded.

[16] Faced with declining ticket sales and deficits, Bronstein immediately launched an aggressive new revenue plan with audience development at the core of its actions.

Because of successful audience development initiatives at the core of the plan as well as other revenue progress and strong management of expenses, the structural deficit (whose gaps are funded by additional contributions) has declined 18% from $3.4M in 2007 to $2.8M in 2011, dipping as low as $2.62m in 2010.

In February 2015, the SLSO named Marie-Hélène Bernard, then-president of the Handel and Haydn Society as its new president and CEO, effective July 1, 2015.

[20] During the scheduled renovation period, the orchestra is to give concerts principally at the Touhill Performing Arts Center of the University of Missouri–St.

[21] In its 140-year history, the St. Louis Symphony Orchestra has earned nine Grammy Awards out of 60 nominations from the National Academy of Recording Arts and Sciences.

[22] In December 2020, the SLSO announced the appointment of Stephanie Childress as its next assistant conductor and music director of the St. Louis Symphony Youth Orchestra, effective with the 2021-2022 season.

[24] In July 2024, the SLSO announced the appointment of Samuel Hollister as its next assistant conductor and music director of the St. Louis Symphony Youth Orchestra, effective with the 2024-2025 season.

In July 2024, the SLSO announced the appointment of Freeman as the next director of the St. Louis Symphony Chorus, with immediate effect.

The IN UNISON Chorus is currently directed by Kevin McBeth, who is also Director of Music at Manchester United Methodist Church in suburban St. Louis.