I add up the years in my head as the women introduce themselves. Between them, I ballpark they've spent more than 200 years behind bars.

As we grab some seats in the visiting room, I tell them I've watched, over and over again, their video of a song recorded at an independent TEDx event inside Muncy state prison in 2014. It's been viewed more than a million times.

watched it again in the parking lot before I walked in, I tell them.

They are visibly pleased. Their voices reach beyond the steel bars in a way most of them never will.

​The women, dressed in identical rust-colored uniforms, are lifers, which in Pennsylvania means they are serving life without the possibility of parole.

For their crimes, mostly murder or related offenses, they have been imprisoned for decades, and save for a change in the law or a compassionate release in the final stages of a terminal illness, they will die here.

For their crimes, they deserve to be punished. No argument.

As the words in their song,  "This Is Not Our Home," go:

I'm not saying that I'm not guilty

I'm not saying that I shouldn't pay

I'm just asking for mercy …

I have to have hope that I will be free one day.

The song is a gut punch, an emotional commentary on incarceration and redemption in a broken U.S. criminal justice system.  It was performed by 10 lifers, half of whom are in the room when I visit. It was written by a psychologist at the prison, Howard Woodring.

"I never realized how resilient the human spirit was until I watched these ladies make a life for themselves here, because you have to, because you have to hang on," he said.

His hope, he said, getting choked up, was that the song started a conversation among the public and lawmakers, that it got people thinking and talking about crime and punishment, rehabilitation and redemption.

From the very first time I watched the video, I wondered: What could become of these women aging in prison if they were released?

From their song again:

This is not my home

I dream of freedom

Hope for mercy

Will I see my family?

Or die alone?

During our meeting, they all wanted to be clear on one thing: They don't want victims to be lost in the conversation. They just want "the free world," as 72-year-old Lena Brown calls the world beyond the prison walls, to consider that they have more to offer.

I have never lost someone I cared about at the hands of another person. My belief in redemption has never been tested, not truly. But listening to Brown, whom everyone calls "Bird," I found myself trying to reconcile her past with her present, the woman who plunged a knife into another human being with the nuturing fragile woman sitting before me.  Did these women deserve compassion? Did these admitted killers have any humanity worth saving?

As if reading my mind, LaShawna Bennett spoke. She'd slipped in while I was talking to the women about the power of music to set them free, if only until the last note. Naomi Blount has been in prison for 34 years but still pines for the tabletop piano she got when she was 8,  and the loud, rambunctious Philly church she once attended.

Bennett isn't one of the lifers in the 2014 song. She is a short-timer, with only 50 or so days left on a 3½-year drug-related sentence. She's here because she had a role in their latest song, played in front of a packed gym inside Chester state prison last year, and because she's roommates with Brenda Watkins, a lifer who has been in prison for 30 years. She stays only long enough to say something she thinks I need to share with the outside.

"Every woman here has taught me how to do better and be better when I get out," she says. "I am a better woman because I see how hard they try when they have no chance of leaving. If they can help people in here, imagine what they can do on the outside."

"The world may have condemned these women," she says. "But they are not condemned."

As we continue to talk, I look around the room. One of the women in the 2014 video who isn't here was a juvenile when she committed her crime. Under a change in Pennsylvania's mandatory sentencing laws for juveniles, she may go home one day. Theresa Battles, another lifer who stood out in the 2014 video, is also absent.

Last month, Battles died, 45 days after being granted a compassionate release in the final stages of cancer. She was 56. She had been imprisoned for almost 29 years.

She finally got the answers to the questions in their song, Watkins said.

"She did see her family.

"She did not die alone.

"This was not her home."

Watch the video. Listen to the women sing, and ask yourself: Is there a way to acknowledge the victims while also acknowledging that these women can still have an impact on the free world?