The official parody musical of the bestselling erotic novel "Fifty Shades of Grey" by E.L. James is already selling out at performance locations around the country. 

Created by a comedy troupe called Baby Wants Candy, "Fifty Shades! The Musical" opened at the Apollo Theater in Chicago last month. It is now selling out for its brief January run in New York.

Even though the troupe has spent nothing on advertising, the musical's demand is a testament to the extreme popularity of the book, which has sold more than 3.2 million copies worldwide, the Daily Mail notes.

According to the Chicago Tribune's Chris Jones, who reviewed the musical during its Apollo run, the theater "had never ever seen a crowd like this."

Jones calls "Fifty Shades! The Musical" "a little collection of modestly amusing sketches and original songs, partly celebrating the daring raunch of the original book, and partly lampooning its central characters."

But he suggests that people who are seeing the parody hoping for close similarities to the book will be disappointed. 

The lusty main character of "Fifty Shades," Christian Grey, has a potbelly in the musical, for example, according to the Mail. 

"A couple of male dancers showed up and cavorted a little in the background," Jones wrote.

"[But] that's not enough for all these women in the audience, I thought to myself. They're looking for more."

The musical includes 11 original songs with titles such as "They Get Nasty," "I Don't Make Love, I F#*!," and "There's a Hole Inside of Me," backed by a live band, as well as plenty of dance numbers.

The premise of the musical is that a ladies' book club meets to read "Fifty Shades of Grey," but the reading soon unravels into a real life comedic rendition of the book. 

"Fifty Shades! The Musical" is playing in New York City at the Gramercy Theater on Jan. 11 and Jan. 12, and in New Jersey at Union County Performing Arts Center on Jan. 13.

Tickets are available at Ticketmaster.