The 13ft long metal pipe, estimated to have weighed around 100kg, crashed into the audience roughly 30 minutes into the event in Vassa, west Finland.
Shocking footage from the scene shows people screaming as more of the ceiling fitting fell away into the crowd, while band members on stage leapt away from the ensuing chaos.
Roughly 4,000 people were there to witness the terrifying spectacle at the Raskasta Joulua event – which translates as Heavy Christmas.
The event features high profile Finnish bands – including the former singer of Nightwish Tarja Turunen – performing Christmas jingles in a heavy metal style.
However despite the horror of the ceiling crashing down around them, audience members were reportedly quick to help.
Witnesses and emergency service officials both noted the measured response from concertgoers, who lifted the metal piping without panicking to help those trapped underneath.
Seven people were later taken to hospital with minor injuries, fire official Ari Rinta-Jaskari confirmed.
He said: “It is still unclear what caused the pipe to fall.
“The seven people injured were taken to Vaasa Central Hospital for a check up.”
Speaking to regional publication Vasabladet, eyewitness Jari Anturanniem said: “It’s shocking that something like this can happen, and why now?
“They’ve been holding lots of concerts in the ice hockey arena all autumn.
“We had our seats on the stands and could see it all.
“The pipe that came through the air, a 1.2 meter diameter pipe, fell off in the middle and dropped straight onto the crowd.
“I work in the industry myself and know that there are not light things, the tube weighs about 100 kilograms.