This blind teen went viral for singing the national anthem. He hopes his voice will bring joy to others.

Sawyer McCarthy communicates best through music. The 13-year-old from South Carolina is blind. But his other senses — like his voice — are strong. 

In April, he sang the national anthem at a Columbia Fireflies game, reaching millions of viewers — not only in America but around the world. 

"I remember asking him one day, 'How many people do you think saw your video?'," his mom, Brianna McCarthy, told CBS News, turning to her son. '"You answered me and you said, 'Four.' I said, 'Yeah, try like four million.'"