Ryan Cleary, 20, and Jake Davis, 19, pleaded guilty to Interfering With The Beats of An Established Recording Artist At The Height of His Powers, a crime that carries a minimum sentence of seven years.
Jarre's concert in Paris was thrown into chaos in 2009 when the two hacked into his set and swapped it for a series of fast-paced traditional German tunes.
CCTV footage shows waves of confused concert-goers at first bouncing to Jarre's music before violently dipping their knees and bobbing up and down as the oom-pah-pah kicks in.
Dozens of members of the public were treated for heat exhaustion as the pace became increasingly frantic and people were knocked over.
The pioneer of electronic music put his hands on his head in horror and was heard to shout: "My synths, my ice-cold synths. What have you done?"
He attempted to switch to a stand-by keyboard but found that instead of it being loaded with his own tracks, it merely played a traditional bossa nova beat recorded on a Bontempi organ.
The hackers also tampered with a back-projected film made for the concert, replacing an artfully directed montage of ice floes and rainforests with a screening of the Ted Danson film Getting Even With Dad.
Cleary and Davis have also pleaded guilty at Southwark Crown Court to plotting to bring down high-profile websites and hack into the computers of government agencies, media companies and IT security firms.
Jarre is also suing the Britons, whom he says wiped out his entire back catalogue on the night of the gig, leaving him only with Bavarian ditties to play at gigs.Tweet