The building is essentially a circle with a 120-foot diameter covering 17,000 square feet, with a large vestibule on the north side, and 396 lights in its copper dome.

[2][3] Originally dedicated to the composer Edward MacDowell, the building was rededicated on April 26, 1985, in honor of Helene Foellinger, whose gift to the university enabled the facility to undergo a major renovation.

[4] The idea for an Auditorium began in 1905 with the university's president, Edmund Janes James, who wanted to build a "noble monument" dedicated to the art of music.

Unfortunately the state legislature only authorized $100,000 which necessitated Blackall making some drastic changes in his design, which originally called for an auditorium that would cover 30,000 square feet (2,800 m2), have a copper dome with a smaller glass oculus, and 2,500 seats,[2] as well as a south wing which would be the home for the School of Music.

"[3] Several weeks before the dedication of the building was scheduled, Blackall learned that the hall was acoustically imperfect, with what President James called "A fearful echo."

Fixing the hall's sound was assigned to the professors of the university's Physics Department, in particular Floyd Rowe Watson, who knew very little about acoustics, but spent six years solving the problem, after which he was a recognized authority of the subject.

[9] The Lorado Taft sculpture Alma Mater, which now stands outside Altgeld Hall, was originally placed outside the south end of the Auditorium, where two fragments of the sculptor's Fountain of Creation are now located.

However, thanks to a $3 million gift in 1983 from newspaper publisher Helene Foellinger (Class of 1932) of the Fort Wayne News-Sentinel, the auditorium was instead renovated again, built and refinished to Blackall's original design under the supervision of architect Walker Johnson, who utilized Blackall's original plans and drawings, as well as tinted lithographs.

[3] The auditorium has a camera atop it which captures live video of the Main Quad, which can be accessed on the Illinois website.