In 2008, Boston musician Chadwick Stokes jumped trains across the Great Plains to Denver. It was an unusual way to get to a gig — his then-band State Radio was playing with Rage Against the Machine at a protest show during the Democratic National Convention. But it was hugely influential in how Stokes sees the world and writes songs.

“Mostly it’s the people that you meet, where are they going and why are they going there,” Stokes told the Boston Herald. “They are people that feel unseen by the American dream and are taking matters into their own hands.”

Years after that epic train trip, Stokes conjured his own character removed from the American Dream. Hannah was a young woman train-hopping across the country to donate her liver to her dying brother. But when Roe v. Wade was overturned by the Supreme Court in 2022, Hannah’s story changed and grew into a rock opera about a woman riding the rails to Chicago to obtain an illegal abortion in 1972.

“I’ve been wanting to write a rock opera for 30 years and for the last 10 years I’ve been sitting on this protagonist, Hannah, trying to figure out why she’s on these trains,” Stokes said. “When Roe was overturned, it was like, ‘This is what it is about.’ Now Hannah is much more in focus.”

Stokes has been workshopping his rock opera, “1972,” for over a year at gigs. On April 4, Stokes and band will perform a fully revised and mostly ready version of “1972” at the Somerville Theater for the Calling All Crows annual benefit — Calling All Crows is a non-profit organization founded by Stokes and his wife, Sybil, dedicated to connecting music fans to women’s issues both at home and abroad.

Since his days in arena-filling band Dispatch through his solo albums, Stokes has written narrative songs. But this is the first time his childhood obsession with the rock musical has bloomed in full.

“I loved ‘Tommy’ as a kid, loved ‘The Wall,’ loved the musical and movie ‘Hair,’ ” Stokes said. “My parents, when they lived in New York City, saw like the second night of ‘Hair’ when it came out… It was always on the record player when we were kids.”

With each performance of “1972,” the piece has taken a step toward becoming a stage production.

“Some songs get cut, some songs get added, some remain mostly the same with just little tweaks,” he said. “I’ve never sat on a group of songs this long. I think I was a bit spoiled by the looseness of the rock world.”

Next, things will get even tighter. While Stokes wants to tour Hannah and her story of escaping a violent relationship with a tour later in the year, he has already started building a creative team for a traditional musical stage show. Auditions for actors and dancers are coming soon.

“1972” is a completely new endeavor for Stokes. But its mix of art and activism is familiar. Since the ’90s and his work with Dispatch, Stokes’ output has largely centered on the fight for justice, justice for those unseen by the American dream.

“If this rock opera was unrelated to the crisis we are all in now, I’m not sure it would have legs,” he said. “We’d probably table it for something that feels more immediate or more helpful.”

For tickets and details, visit chadwickstokes.com

Chadwick Stokes wrote his rock opera “1972” about a woman riding the rails to Chicago to obtain an illegal abortion in 1972. (Photo David Andrako)