Head Band is the first part of the 5th aired and 4th produced episode in season 4 of Dexter's Laboratory, which first aired on May 16, 2003. In this episode, Dee Dee gets the Boy Band Virus, which causes everyone to sing what they say, stuck in her ear. Dexter tries to get rid of it, but he and Mom end up catching it as well.
Dee Dee gets a song stuck in her head, which is actually a virus. Dexter and Mom soon catch it, and Dexter has to reverse the effects of this. He succeeds at the end, not knowing that Dad also caught it.