The highly anticipated guest spot seems only natural.  “Defying Gravity,” the defining song of Menzel’s Tony Award-winning role in Wicked, has already made an appearance. So has her Wicked co-star, Kristin Chenoweth. Broadway fans have another theory regarding Menzel’s casting. Ryan Murphy, who created the series about a misfit high school glee club, has acknowledged in interviews that “Glee” star Lea Michele and Menzel share “an almost spooky resemblance.” Despite that, he denies that Menzel is being brought in to play Michele’s biological mother (her character, Rachel, has two dads). Instead, he says, Menzel will play the coach of rival glee club, Vocal Adrenaline.

Amid speculation that Menzel will appear in all nine new episodes, Murphy says only that she will be in the first episode back on April 13 and in the season finale.

It seems fans will just have to wait and see how Idina Menzel figures in the show. In the meantime, the speculation continues: What’s she going to sing?!

— Gemma Wilson