They are the High Hopes Choir and sang to more than 75,000 people at the Croke Stadium in Dublin, including Pope Francis.
It is Ireland's first homeless choir. It was founded in 2014 by conductor David Brophy.
The choir has not only participated in major events, such as the World Meeting of Families, but also collaborated with renowned artists such as Shane Filan and Ed Sheeram.
For Pope Francis they sang the song “High hopes” by the Irish group Kodaline.