One of the features includes an exaggerated Adam's Apple. Definitely a guy.
The long, bright white hair was supposed to invoke the hairstyles of male punk rockers at the time, but somewhere along the way, it was decided that the Electric Mayhem required a feminine aspect. So this already girly looking character became Janice, based on female musicians like Janis Joplin.
During the first season of The Muppet Show, Janice was voiced by Eren Ozker, taking over from Fran Brill who voiced her in the pilot. Brill, known for characters like Prairie Dawn, had given Janice a high-pitched voice, unsuited to her rock and roll atmosphere. Ozker, however, gave her a sexy, husky voice that invoked Joplin's signature style. However, Janice's singing voice was never featured during Electric Mayhem's songs. The only chance to hear her sultry voice was during her role as Nurse Janice during the Veterinarian's Hospital sketches.
Ozker left after the first season, allowing Richard Hunt to step in as Janice's performer. He created the Janice we are familiar with today, with a valley-girl attitude and vocabulary that was previously not present. Still, Janice was not offered many solo singing roles, due to her voice no longer fitting the intended persona for the lead guitarist. She became Floyd's love interest and would be found singing love-themed duets with him.
Her biggest solo number, fittingly, was "With a Little Help from My Friends."
What would you do if I sang out of tune?
Personally, I was a fan of the original Janice. The voice and personality seemed more appropriate to the Electric Mayhem's nature and the "valley-girl" speak feels a little forced and unnecessary at times. She does not act like a spoiled brat, nor does she appear ditzy. But the "fer sures" and "rullys" have replaced most of her character traits.
Like, oh my gosh, ya know?
However, Richard Hunt realized the potential that this one-dimensional character had. Because the other Muppets were so well defined, he could add anything he wanted to Janice's character and make it part of her personality. These ad-libs became apparent in the Muppet films, in which Janice would find herself in the embarrassing situation of talking during conversational lulls.
Those small, random moments make Janice one of the most unconventionally funny Muppets of the main gang. Her random thoughts take on a more risque nature than the Muppets are usually associated with. In public appearances, the puppeteers have fun exploring the sexuality of the token "hot girl" Muppet. At Muppetfest in 2001, some the puppeteers and their Muppets took turns answering questions from fans. This resulted in the following exchange:
Question: (to Floyd Pepper) "Are you still tight with Janice?"
Floyd: "Well, Janice ain't so tight anymore."
(The audience laughs, shocked.)
Elmo: "Elmo doesn't understand the question. Could you explain the question, Mr. Floyd? 'Cause Elmo learned on Sesame Street - if you don't understand something, always ask!"
Janice: Reminding us that the Muppets aren't always for kids since 1975.