CHICAGO — Promotional nights have been a part of baseball games for years, but there will never be anything like what happened at Comiskey Park on July 12, 1979.

On that night, a radio promotion led to an on-field storming, a forfeit for the White Sox and a longtime debate on what the night really represented.

This is Disco Demolition Night: A promotion featuring popular WLUP disc jockey Steve Dahl and his quest to destroy records featuring disco music — a genre he despised and made fun of on the air during his shows.

Disco Demolition Night was held during a double-header against the Tigers with the White Sox trying to build momentum in what had been a disappointing 1979 up to that point. Two years removed from a 90-win season, the club had won just nine games in April and June but entered Disco Demolition Night with seven wins in their last eight games.

As part of the promotion with WLUP, fans could get a 98 cent ticket to the doubleheader if they brought a disco record with them to sell. It was expected to draw a few thousand extra fans but instead, the contest officially drew 47,795 — the largest crowd of the year.

It’s estimated that over 50,000 eventually made their way into the ballpark.

The turnout, naturally, featured a mostly anti-disco crowd who had plenty of signs and often changed “disco sucks” during the evening.

After a 4-1 White Sox loss to the Tigers in Game 1, the albums were blown up in center field, much to the delight of the fans. After things settled down for a bit, people started to trickle onto the field as the White Sox began to warm up for Game 2.

Then a sea of people invaded the playing surface and eventually it was covered with fans.

Owner Bill Veeck and announcer Harry Caray pleaded with the fans to return to their seats, a alert was put on the scoreboard with the same message, and even the lights were dimmed in hopes of restoring order.

None of it worked as a bonfire was set in the center field and a batting cage was destroyed right around it while the grass was damaged around the field. The bases were taken as well during the little under 40 minutes that the fans had their run of the field.

With an estimated 7,000 fans on the field, Chicago police were called in and eventually were able to get the crowd under control. Cheers came down from the crowd as the fans were finally led off with 39 people arrested for disorderly conduct.

With the field torn up and Tigers manager Sparky Anderson refusing to let his team play out of safety concerns, the decision was made initially to postpone the second game of the doubleheader to a later date. It was later determined that the White Sox would forfeit the game since they couldn’t provide an adequate playing field for the contest.

The interpretation of what happened that night has changed through the years, with the initial negative reaction that came in the sports pages in Chicago newspapers representing the many opinions on the event. Some have said its disastrous promotion ever while the incredible crowd turnout made others argue it was the most successful.

Some have blamed it for the downfall of disco music, which had found popularity in the late 1970s. In a documentary from HBO in 2020, the Bee Gees said they shifted away from the genre after Disco Demolition Night and began to produce for other artists.

Some have even credited the birth of house music to the event, as detailed in this 2019 report by VOX.

On the 40th anniversary of the event, WGN’s Mike Lowe did a story about the complicated legacy of the event. See by some as a radio promotion gone wrong, others now view Disco Demolition Night as “racist and homophobic.”

In a 2019 interview with the Chicago Tribune, Dahl responded to the criticism of the event.

“We blew up disco records, made fun of the Bee Gees and ‘Saturday Night Fever.’ It goes no deeper than that,” Dahl said in that interview. “Perception is not always reality. Especially when that perception uses the prism of today to look at events 40 years ago. Sometimes a stupid radio promotion is just a stupid radio promotion.”

No matter what the thoughts of the event, it remains a significant sports and cultural moment in the history of Chicago.