The Zack Files - Season 2 Episode 4 Groovin'

Gwendolyn is hosting a party and she needs a DJ, so Vernon and Zack tries out. While Zack was trying to practise on his (terrible) DJ skills, he spun a record backwards, and hears something, a message. Spencer was there to stop him, but he did not stop the transfer of DNA to Zack that made him a ""Cool Dude"" Beatnik from the 1960's. During the tryouts, the people did miserably. But when Zack came on the scene, he made a dazzling performance and impressed Gwen, so she let him become the DJ. When Spence and Cam experiments on Zack and tries to reverse the process, Zack plays the record backwards again. Unfortunately, it did not work and Vernon became another copy of what Zack was. Now they have two people who are groovy.