Festival Hall closed the east end of the South Gardens and faced west across the pools to the Palace of Horticulture, its green dome and cupolas answering the other building's glass bubble. The Official Guide compared it to the Théâtre des Beaux-Arts in Paris. Todd put it more plainly: a "large and properly festive sort of structure in the French theatrical style, giving the impression of being all portals and foyers and audience hall, as in the main it was." It was not an exhibit palace but the fair's principal auditorium.
Its heart was an organ built by the Austin Organ Company of Hartford, which the Guide listed at about 7,000 pipes and 113 speaking stops on four manuals. Todd called it the "forty-thousand-dollar organ." Edwin H. Lemare of London was engaged for 100 noon recitals, and other organists filled the days he did not play. An echo organ hung inside the dome from the ring truss, balanced by a box of sand on the opposite side.
The hall was booked through the whole season. The Boston Symphony under Karl Muck, four concerts by Camille Saint-Saëns, massed band concerts, the Chicago Apollo Club, the Ogden Tabernacle Choir and Loie Fuller's dancers are all on the Guide's program. The hall was built to seat 2,800, and a short experience of the season showed that was not enough, so galleries were added. John D. Barry's architect-companion remarked that the acoustics turned out badly and the interior had to be remodeled.
The building was always meant to lose its organ. The instrument was a working exhibit, earmarked from the start for the city's new Exposition Auditorium in the Civic Center, where it was installed and dedicated by Lemare on April 8, 1917.
