Wikipedia
A tagada is an amusement ride made by various manufacturers. Riders sit in a round bowl with no seatbelts or restraints. There are bars behind the riders which they hold on to. The ride starts to spin, the music starts playing and hydraulic arms bounce the riders up and down.
The Tagada is operated by a human operator who will synchronize the bounces with the music beat. Most operators give time for riders to get to their seats again before making the ride bounce (this occurs if turbulence is too strong). Sometimes riders will be told the ride is over and the gates will not open and the operator will restart the ride making everyone fall over and then open the gates.
Tagada rides are often associated with injuries to the occupants, including ejections from the ride, such as 20 June 2011 in Newcastle, or during the 2008 British Grand Prix or October 2009, or just broken bones of riders who fall into the middle of the ride. Many street fairs ban tagada rides due to their generally poor safety records and cleanliness.