On This Day in Pittsburgh History: September 10, 1971 
Heinz Hall, formerly Loew’s Penn Theatre, reopens in grand fashion with a performance by the Pittsburgh Symphony Orchestra. [Wikipedia; Explore Pittsburgh] 
From Music: Recycled Centers, Time magazine, December 1971: 

There are two ways for a city to acquire a cultural center. One is to clear a downtown neighborhood and erect an entire new complex—at a tremendous expenditure of money, time and public inconvenience. New York’s Lincoln Center cost $184 million, took ten years to complete, and disrupted traffic and residential life over a 14-acre area for much of that time. The other way is to take an existing theater, such as an abandoned movie palace, and simply refurbish it. This more modest method may produce less grand results, but it is cheaper, quicker and less traumatic for the surrounding community.
In recent years several cities—frustrated by inadequate, outdated facilities but pressed for funds and space—have turned to the second way. St. Louis converted an old Loew’s Orpheum into Powell Hall, now the home of the St. Louis Symphony. Youngstown, Ohio, adapted the former Warner Theater not only for its symphony orchestra but for new opera and ballet companies. Similar projects have been carried out in Houston and Los Angeles, and Cedar Rapids, Iowa, is eagerly investigating the idea.
Good Throw. Most impressive of all these recycled centers is Pittsburgh’s Heinz Hall for the Performing Arts. It stands on prime real estate, in the so-called Golden Triangle area, just at the point where the Allegheny and Monongahela rivers meet to form the Ohio. The former Penn (movie) Theater, it was reclaimed from the wreckers in 1968 for $800,000, then remodeled for around $10 million in only 15 months. Since its opening last fall, Heinz Hall has become the focal point of an energetic renaissance of Pittsburgh’s artistic life. It is in regular use by the Pittsburgh Opera, Civic Light Opera, Pittsburgh Ballet, Pittsburgh Youth Symphony, and its owner and principal constituent, the world-class Pittsburgh Symphony under Conductor William Steinberg.
Last week Steinberg led the orchestra through a program of Shostakovich and Mozart that, besides being musically rewarding, demonstrated that the auditorium is an acoustical gem. Heinz Hall has what is called a good throw. Its sound reaches the audience in smooth, vibrant, evenly distributed waves. German Acoustician Heinrich Keilholz removed a lot of old velvet, surrounded the stage with reflector panels (removable for opera and ballet), then hung a larger, fan-shaped reflector out over the main floor. “In the old days,” says Steinberg, “Pittsburghers had no way of telling what their orchestra really sounded like. To find out, they had to go hear us play in Carnegie Hall in New York.” (more) 

On This Day in Pittsburgh History: September 10, 1971 

Heinz Hall, formerly Loew’s Penn Theatre, reopens in grand fashion with a performance by the Pittsburgh Symphony Orchestra. [WikipediaExplore Pittsburgh

From Music: Recycled Centers, Time magazine, December 1971: 

There are two ways for a city to acquire a cultural center. One is to clear a downtown neighborhood and erect an entire new complex—at a tremendous expenditure of money, time and public inconvenience. New York’s Lincoln Center cost $184 million, took ten years to complete, and disrupted traffic and residential life over a 14-acre area for much of that time. The other way is to take an existing theater, such as an abandoned movie palace, and simply refurbish it. This more modest method may produce less grand results, but it is cheaper, quicker and less traumatic for the surrounding community.

In recent years several cities—frustrated by inadequate, outdated facilities but pressed for funds and space—have turned to the second way. St. Louis converted an old Loew’s Orpheum into Powell Hall, now the home of the St. Louis Symphony. Youngstown, Ohio, adapted the former Warner Theater not only for its symphony orchestra but for new opera and ballet companies. Similar projects have been carried out in Houston and Los Angeles, and Cedar Rapids, Iowa, is eagerly investigating the idea.

Good Throw. Most impressive of all these recycled centers is Pittsburgh’s Heinz Hall for the Performing Arts. It stands on prime real estate, in the so-called Golden Triangle area, just at the point where the Allegheny and Monongahela rivers meet to form the Ohio. The former Penn (movie) Theater, it was reclaimed from the wreckers in 1968 for $800,000, then remodeled for around $10 million in only 15 months. Since its opening last fall, Heinz Hall has become the focal point of an energetic renaissance of Pittsburgh’s artistic life. It is in regular use by the Pittsburgh Opera, Civic Light Opera, Pittsburgh Ballet, Pittsburgh Youth Symphony, and its owner and principal constituent, the world-class Pittsburgh Symphony under Conductor William Steinberg.

Last week Steinberg led the orchestra through a program of Shostakovich and Mozart that, besides being musically rewarding, demonstrated that the auditorium is an acoustical gem. Heinz Hall has what is called a good throw. Its sound reaches the audience in smooth, vibrant, evenly distributed waves. German Acoustician Heinrich Keilholz removed a lot of old velvet, surrounded the stage with reflector panels (removable for opera and ballet), then hung a larger, fan-shaped reflector out over the main floor. “In the old days,” says Steinberg, “Pittsburghers had no way of telling what their orchestra really sounded like. To find out, they had to go hear us play in Carnegie Hall in New York.” (more

On This Day in Pittsburgh History: June 17, 1973

Sponsored by Gay Alternatives Pittsburgh, the city holds its first Gay Pride Week as 150 people march from Downtown to Schenley Park. [Pittsburgh Post-Gazette]

For a great read, this dissertation discusses social movements in Pittsburgh from 1960 to 1980, including the origins of Pride Week.