Answer by taking a quote from the following article:

The Rock and Roll Hall of Fame, located on the shore of Lake Erie in downtown Cleveland, Ohio, recognizes and archives the history of the best-known and most influential artists, producers, engineers, and other notable figures who have had some major influence on the development of rock and roll. The Rock and Roll Hall of Fame Foundation was established on April 20, 1983, by Atlantic Records founder and chairman Ahmet Ertegun. In 1986, Cleveland was chosen as the Hall of Fame's permanent home. Since opening in September 1995, the "Rock Hall" - part of the city's redeveloped North Coast Harbor - has hosted more than 10 million visitors and had a cumulative economic impact estimated at more than $1.8 billion.

There are seven levels in the building. On the lower level is the Ahmet M. Ertegun Exhibition Hall, the museum's main gallery. It includes exhibits on the roots of rock and roll (gospel, blues, rhythm & blues and folk, country and bluegrass). It also features exhibits on cities that have had a major impact on rock and roll: Memphis, Detroit, London and Liverpool, San Francisco, Los Angeles, New York and Seattle. There are exhibits about soul music, the Fifties, Sun Records, Atlantic Records, hip hop music, Cleveland's rock and roll legacy, the music of the Midwest, rock and roll radio and dee-jays, and the many protests against rock and roll. This gallery also has exhibits that focus on individual artists, including the Beatles, the Rolling Stones, Jimi Hendrix and others. Finally, the Ahmet M. Ertegun Exhibition Hall includes two theaters, one of which features a film about the roots of rock and roll and one that features films on various subjects.  The first floor of the museum is the entrance level. It includes a cafe, a stage that the museum uses for various special performances and events throughout the year, and a section called "Backstage Stories." The second floor includes several interactive kiosks that feature programs on one-hit wonders and the Songs That Shaped Rock and Roll. This level also includes a gallery with artifact-filled exhibits about Les Paul, Alan Freed, Sam Phillips and the evolution of audio technology.  Visitors enter the Hall of Fame section of the museum on the third floor. This section includes "The Power of Rock Experience," which includes one of Jonathan Demme's final works, a film shown in the Connor Theater. The film includes musical highlights from some of the Hall's induction ceremonies. Visitors exit the Hall of Fame section on the fourth floor. That level features the Foster Theater, a state-of-the-art 3-D theater that is used for special events and programs.  Finally, the top two levels of the Rock and Roll Hall of Fame feature large, temporary exhibits. Over the years, numerous exhibits have been installed on these two levels, including exhibits about Elvis Presley, hip-hop, the Supremes, the Who, U2, John Lennon, the Clash, Bruce Springsteen, Women Who Rock, and the Rolling Stones.

What about the fourth floor of the Rock and Roll Hall of Fame?
Visitors exit the Hall of Fame section on the fourth floor.