Fifteen-year-old Gianna Isabella of Jackson, N.J., is no ordinary "American Idol" contestant.

Gianna is the daughter of 1980s pop star Brenda K. Starr, whose song "I Still Believe" reached No. 13 on the Billboard Hot 100 in July 1988. The song was covered 10 years later by Mariah Carey, who sang backup on the original 1987 recording, according to "the essential 'American Idol' fan site,", which also compares Starr's 1988 video with Carey's 1998 edition.

When Gianna introduced herself as Brenda K. Starr's daughter, "American Idol" judge Jennifer Lopez lit up, saying, "I know Brenda, from back in the day."

"I grew up in Manhattan. I actually used to go to the same dance studio as J. Lo to rehearse for my shows with my choreographer," Starr said on "American Idol." "Then I saw her as a Fly Girl ("In Living Color") and I was like, oh my god! and knew she was going to make it."

In her audition, Gianna sang a powerhouse version of the 1964 song, "House of the Rising Sun," by The Animals.

"Good job sweetie," Lopez said to Gianna. "Your mom would be proud."

"I'm very inspired by my mom," said Gianna. "I would have to say she's my idol. So I just want to show her how her hard work of teaching me is paying off. I just want to show her how proud I am to be her daughter."

Gianna's pride in her mother is reciprocated.

"My daughter is the best thing that ever happened to me. She's everything a mother could ever ask for," Starr said between tears.

Before the judges gave Gianna their decision, Lopez asked Gianna if she would bring her mother in to say hello.

As the old friends hugged, Lopez said to Starr, "Remember when we were in the dance studio and you were trying to help me to sing?"

"And she was trying to teach me to dance!" Starr said back.

Judge Keith Urban invited Starr to sit in his judges' seat and asked what she would tell Gianna if she were given a vote. "I would tell her that she made it because she works so hard. She loves it," said Starr. "Her friends go out, parties, and she stays home and writes and sings all day long. She's such an amazing daughter."

Her hard work paid off. Gianna got a ticket to Hollywood.