How Live? (Performance)

[Jazlikethat]

Hey whenever I see bands perform live that use electronic elements I always wonder exactly how live they are. Like what portion of the music is prefabricated and how much is created on stage.

This performance is baffling me.
http://www.youtube.com/watch?v=OLOqCWX4BOQ

Ignore the humor for a bit . At first I thought it was being performed live when I saw the key player really goin' at it, but by then end I start to see some iffy bits with the playing and also the song is perfectly synced to a video and sounds just like their album version. What do you guys think they're doing?

[uethanian]

that was very strange.

uh seems to me like 'justice' is a DJ group like daft punk. the guys on stage don't seem to be doing anything. the singer is definitely not singing, the bass is synth, i can't even hear a guitar in the song...

[benjo09]

Ye they are a dance group. Thats them at the end.