Jay Pritzker Pavilion, also known as Pritzker Pavilion or Pritzker Music Pavilion, is a bandshell in Millennium Park in the Loop community area of Chicago in Cook County, Illinois, United States. It is located on the south side of Randolph Street and east of the Chicago Landmark Historic Michigan Boulevard District. The pavilion was named after Jay Pritzker, whose family is known for owning Hyatt Hotels. The building was designed by architect Frank Gehry, who accepted the design commission in April 1999; the pavilion was constructed between June 1999 and July 2004, opening officially on July 16, 2004. Pritzker Pavilion serves as the centerpiece for Millennium Park and is the home of the Grant Park Symphony Orchestra and Chorus and the Grant Park Music Festival, the nation's only remaining free outdoor classical music series. It also hosts a wide range of music series and annual performing arts events. Performers ranging from mainstream rock bands to classical musicians and opera singers have appeared at the pavilion, which even hosts physical fitness activities such as yoga. All rehearsals at the pavilion are open to the public; trained guides are available for the music festival rehearsals, which are well-attended. Millennium Park is part of the larger Grant Park. The pavilion, which has a capacity of 11,000, is Grant Park's small event outdoor performing arts venue, and complements Petrillo Music Shell, the park's older and larger bandshell. Pritzker Pavilion is built partially atop the Harris Theater for Music and Dance, the park's indoor performing arts venue, with which it shares a loading dock and backstage facilities. Initially the pavilion's lawn seats were free for all concerts, but this changed when Tori Amos performed the first rock concert there on August 31, 2005. The construction of the pavilion created a legal controversy, given that there are historic limitations on the height of buildings in Grant Park. To avoid these legal restrictions, the city classifies the bandshell as a work of art rather than a building. With several design and assembly problems, the construction plans were revised over time, with features eliminated and others added as successful fundraising allowed the budget to grow. In the end, the performance venue was designed with a large fixed seating area, a Great Lawn, a trellis network to support the sound system and a signature Gehry stainless steel headdress. It features a sound system with an acoustic design that replicates an indoor concert hall sound experience. The pavilion and Millennium Park have received recognition by critics, particularly for their accessibility; an accessibility award ceremony held at the pavilion in 2005 described it as "one of the most accessible parks – not just in the United States but possibly the world".