You might as well stop imagining what the lyrics to Van Halen's "Jump" would sound like sung to the tune of John Lennon's "Imagine."
Someone named Mighty Mike actually did the mash-up and posted it on YouTube, where it came to the attention of Foo Fighters. Next thing you know, Dave Grohl and company did it in rehearsal and posted video of that on Facebook, thanking Mighty Mike for the inspiration. But it doesn't end there.
The Foos played it during their Friday night show in Curitiba, Brazil, where a fan captured a lot of the song on video.
Source: Ultimate Classic Rock