Then came fan art, fan fiction and fan covers of the songs on social media. When the show opened off-Broadway last month, it sold out entirely. In February, Be More Chill will move to Broadway.

“Be More Chill” is already a Broadway Cinderella story. A tale of nerdy teen angst and technology by songwriter Joe Iconis and bookwriter Joe Tracz, this geek-love, sci-fi, high school musical ...