Gladys Knight and Deborah Gibson have signed on to be judges on Fox's "American Juniors." The TV talent show is the spinoff to the network's "American Idol." In addition to Knight and Gibson as regul

Gladys Knight and Deborah Gibson have signed on to be judges on Fox's "American Juniors." The TV talent show is the spinoff to the network's "American Idol." In addition to Knight and Gibson as regular judges, "American Juniors" will have a different guest judge every week.

"American Juniors," a competition for 6-to-13-year-olds, debuted June 3. The viewing audience will select five winners who will form a singing group.

Grammy-winning R&B singer Knight was previously a guest judge on the second season of "American Idol." Former teen queen Gibson has been most recently been headlining the revival of "Cabaret" on Broadway.

Justin Guarini, the second-place finalist in the first season of "American Idol," will be the guest judge in the "American Juniors'" episode airing tonight (June 17).

"American Juniors" is currently Fox's top-rated show of the summer season. According to Nielsen Media Research, the June 10 episode earned a 3.2 rating/10 share, or 8.7 million U.S. viewers.

Viewer voting will begin with tonight's episode to determine which singers will advance to the next round. The voting results will be shown in a half-hour "American Juniors" episode airing tomorrow (June 18) at 8:30 p.m. ET/PT.