R&B star John Legend and Colombian rocker Juanes hoped to shine a light on America's immigration and incarceration reform by performing outside the Eloy Detention Center in Arizona on Wednesday (20Jan16).

The multiple Grammy winners visited the institution as part of Legend's #FREEAMERICA campaign, which aims to "change the national conversation about America's misguided policies and transform America’s criminal justice system."

During their tour of the facility on Wednesday, Legend and Juanes spoke to some of the 1500 immigrants who are detained at the centre, which is located about 100 miles (160 kilometers) from the Mexican border.

In an interview with The Huffington Post, Juanes admits he was "heartbroken" by what he witnessed in the facility, saying, "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."

Legend also commented on the visit, noting it is important for him to view the reality of life in detention centres firsthand.

"The reason why we're here, one, is because we want to bear witness to what's happening so we could tell the world about it," he said, according to ABC News.

Officials at the centre declined to let the duo perform songs inside, so Legend and Juanes took their concert outside the facility, where they performed on a small stage.

The Grammy winners each played their own tunes, and joined forces to sing Bob Marley's Redemption song, as the dozens of people in the crowd sang along.