Lampooning the state’s idiosyncratic T system has long been a fun pastime for commuters, songwriters and, more recently, people on Twitter. To this day, the chorus to the 1940s song “Charlie on the M.T.A.” still echoes through Boston pubs about a passenger named Charlie who finds himself trapped aboard the T, unable to get off the train.

That familiar folk song is the opening number of the production "T: An MBTA Musical." It's a revival of a sketch comedy bit first seen at ImprovBoston 10 years ago. That concept evolved into a full 2-act production now at the Rockwell Theater in Somerville, with performances on the first and third Fridays through December.

The show even stars Charlie from the song, who looks just like the guy on the CharlieCard now used at T stations. As the show's narrator, Charlie sets the scenes and, as he says in the performance, “gets the characters moving.”

Those characters wend their way around the MBTA system, having adventures in song as they try to get where they're going. Britney Verria plays the role of Alice, a character who many T customers can relate to.

"She's kind of all over the place," Verria said, "just trying to get places, and very frustrated with the T and its inefficiency standing in her way."

The T impeding people trying to get around Boston is a theme throughout the show, said playwright Mike Manship. “There are definitely things about living in Boston where you will get frustrated, and the T is a great metaphor for that,” he said.

But this isn’t just a production designed to bash the T — something Manship admits is easy to do. Rather, he said the musical is a celebration of Boston, and the T is an integral part of the city's identity.

“The T is literally a map of the city, but it's also like a character map of the city,” he said. “You've got Kenmore, where you find that sort of bro culture of the city. And then you've got Central Square, which is its own unique world, and Harvard Square. There are so many different flavors of the different neighborhoods.”

MBTA Musical
Actors portray MBTA cops in the "T: An MBTA Musical." From left to right: Ben Gold, Cassie West and Doug Dulaney.
Courtesy of Mike Manship

Riding the T is a communal experience, and one hilariously captured in the song, "People on the T," which is performed by a chorus of characters one might encounter on the transportation system:

“It’s like I’m having a heart attack, when someone bumps my fanny pack.
I know it’s how you get around, it’s like a prison underground.
The people on the T, they’re the same as you and me.
Where everyone is feeling free, and doing whatever they want.”

Melissa Carubia originated the play’s concept 10 years ago, and she composed all of the music and songs. She chose to title the closing number “The T Within" for a reason, she said.

“The T is part of the quintessential Bostonian experience,” Carubia said. “And just like the T is a part of Boston, by being members of this community, we all become the T.”

And as Charlie reminds the audience, despite all the T's signal problems, derailments and delays, laughter is the best medicine. “We're laughing through all of the pain of what the MBTA does to us.”

"T: An MBTA Musical" can be seen at the Rockwell Theater in Davis Square, Somerville, the first and third Fridays through December. Manship said performances could roll beyond that date if people keep buying tickets.