(Debuted July 17, 1982, Peaked #48, 11 Weeks on the Chart)
"Planet Rock" is one of the songs that is credited as a trailblazing work in the Hip Hop world. And like many Hip Hop and Rap compositions, it heavily borrows from earlier material to create an entirely new sound. The main sythesizer riff is borrowed from Kraftwerk's 1977 song "Trans-Europe Express" and the beat is borrowed from the same group's 1981 song "Numbers." A song from Yellow Magic Orchestra called "Riot in Lagos" is also interpolated into the body of the song. Like many of the early pioneers of the new sound, it wasn't much of a hit immediately, and would remain underground (but most importantly, in the minds and on the turntables of the DJs who provided the backing music for the rappers) for several years before its effect was fully realized.
In short, it was one of the indicators that a new sound was creeping out from the underground, and listeners could let the beat move them. Otherwise, they needed to get out of the way because it wasn't going to be stopped once it built up.