By Rob Brunner
Updated January 15, 1999 at 05:00 AM EST

The four-disc series The Perfect Beats, Vols. 1-4 documents dance music in the period immediately following disco’s demise, when synthesizers still seemed futuristic and the music sounded so artificial and robotic that it was dubbed ”electro.” At its best, this stuff is as inventive and innovative as club music gets (Afrika Bambaataa’s ”Planet Rock,” Kraftwerk’s ”Numbers/Computer World”). But there’s also plenty of dance-floor dreck that should have been left in the early ’80s. B