BERLIN (AP) — A Bavarian court found a folk singer guilty Friday of violating Germany's strict child labor laws for having his 4-year-old son perform on stage with him during an evening concert.

Angelo Kelly, 39, was fined 3000 euros ($3,600) by the Hassfurt administrative court for the 2019 appearance at an open air summer concert with his son William, who sang "What a Wonderful World." The boy is the youngest of Kelly's five children.

"During this performance, the child William stood for at least 30 minutes on the stage where he played along, sang along and interpreted his own song," the cou...