Days later, Riley's mother sent a letter to Albany, N.Y. radio station WGNA to explain what it was like attending the concert with her son, and how much Bryan's music affects Riley.

"When Riley pretends to be Luke, he is a whole other person," his mother Marjorie wrote. "He's not afraid or shy. He has confidence and feels free. Every time Luke turned his hat around during the concert, so did Riley. On our way out of the show, Riley pulled me down and said 'I didn't know all the songs mommy. I need to learn all the songs.' He just loves music. Sorry for such a long letter, but I just want Luke and all other artists to know that their music is a powerful thing and truly helps those with disabilities to express themselves and get through rough parts of their day."

Moved by the story, the station invited Riley and his mother into the studio. They had forwarded the letter to Bryan, who then called in during the visit to speak with Riley directly.

Bryan said that during the concert, he was initially intrigued by the message on the shirt (which he admitted seeing from the stage). And later, he was truly moved once he found out what that message meant. "I'm kinda having some tears on the bus here," Bryan admitted.