The choir's leader Tim Rhys-Evans revealed that he believes they can be "inspirational figures" for anyone who wants to believe in their own ability.
On how he felt ahead of the first live semi-final, he said: "A mixture of exhilaration and sheer terror! Once we start singing, the whole power of what we do will kick in and we'll be fine. After the judges' reaction in the first round, we're now looking forward to the live performance."
Only Boys Aloud were formed in 2010 by Rhys-Evans, with the aim of improving the young members' confidence and well-being.
"We've put the work in since forming in 2010, had a tremendous reception whenever we've performed, so we wanted to bring this to a wider audience," he said.
Speaking about why the choir should win, he added: "We have talent. More importantly we have dedication and commitment, and we can be inspirational figures for anyone out there, from whatever background, to show what music and being part of a young choir can bring.
"Winning would be massive for us. But experiencing the thrill of being part of this mass choir is what keeps us going, and that will last long into the future."
The choir recently told Digital Spy that if they ever lost a single member, they would quit as a whole group.
The semi-finals kick off tonight (May 6) with a two-hour special at 8pm on ITV1. Episodes then air daily until Thursday (May 10).
Each semi-final will feature nine acts performing live for judges Simon Cowell, Alesha Dixon, Amanda Holden and David Walliams.