On Jan. 20 in Arizona, Latin music superstar Juanes and singer John Legend got together to perform an impromptu concert outside of the Eloy Detention Center to bring awareness to the troubling relationship between immigration and mass incarceration.

Both Juanes and Legend announced the concert to their fans with videos on Twitter and Instagram in their respective languages.

A video posted by John Legend (@johnlegend) on Jan 20, 2016 at 11:08am PST

The concert was hosted by #FreeAmerica, an organization founded by Legend that works to help bring attention to and reform the criminal justice system in the United States.

Both Grammy-winning singers took several photos and performed two songs each. They sang together on Bob Marley's "Redemption Song," which #FreeAmerica documented on Twitter.

The informal concert featured an audience of about 100 activists, who were transported to the outskirts of the detention center by a van courtesy of #FreeAmerica.

Before performing, Legend and Juanes took the time to tour the facilities. They were able to talk to the detainees and get a sense of the conditions there.

According to NBC News, while the stars hoped to have the detainees attend the concert, the imprisoned immigrants were not released from their cells to hear the performance.

"It's very hard to understand that someone is deprived of their freedom unjustly, and that's why we're here with our music, with our culture, which is the strongest tool to bring attention and give a voice to those who don't have one," said Juanes.

Legend reiterated Juanes' sentiment, but also gave an idea of the struggles that detainees in the facility have to deal with.

"It's life and death for a lot of people, a lot of people that come here, come through a lot of hardship, physically is very difficult to get here and then every day that your here as an undocumented immigrant you're in danger of being detained again, having you're employer being raided, being separated from your family," Legend explained. "They go through a lot of difficulty here to live the American dream to be able to work and feed their family, but also live freely."

The Eloy Detention Center currently houses over 1,500 inmates, many of whom are Central American youth and their families, waiting to be deported or to have their cases heard, reported Univision.

The detention center has been criticized in the past for the deaths of inmates who committed suicide or died of medical problems. Many of the detainees currently being held have fled their countries seeking asylum.