This is a very popular song by a well-known Catalan music company.
The song is called “La presó del rei de França” (The prison of the King of France), which is a traditional Catalan song, and people usually chant it jumping and saying “lo” following the melody, as you will see in the video. The song became a must for Barça fans because this music company used to play it during the celebrations in Camp Nou of the titles won by the team. It helped that the music company is from Barcelona as well.
Enjoy the previous entries from our Chants series here: