This video will give you chills.
According to FIFA regulations, a national anthem can only be played for a maximum of 90 seconds. To ensure that their entire song is played during the World Cup, some teams have changed the timing of their national anthem, while others, like Chile, simply let the song cut out.
David Ramos / Getty
But instead of stopping after 90 seconds, Chile fans have continued singing their anthem a cappella, sending an intimidating echo throughout the stadium.