Gianna is the daughter of acclaimed pop singer Brenda K. Starr. In 2014, she won the ‘New York Dream Night Talent Search’ competition.
Gianna auditioned in Philadelphia, Pennsylvania, with "The House of the Rising Sun" by the Animals and received a golden ticket to Hollywood. She advanced past Hollywood's Lines of Ten, Group Round, and performed "One Night Only" by Dreamgirls for her Hollywood Solo round. She then advanced to Showcase week where she performed "I Still Believe" by her mother, Brenda K. Starr, and advanced to the Top 24. During the Top 24, she performed "I Put a Spell on You" by Screamin' Jay Hawkins and performed a duet with Nick Fradiani singing his coronation song "Beautiful Life". Afterwards, she advanced to the Top 14 where she performed a reprise of "I Put a Spell on You" by Screamin' Jay Hawkins for America's Vote. She secured herself a spot in Season 15's Top 10 where she performed "Listen" by Beyonce. However, she was eliminated in a double elimination with fellow contestant Olivia Rox finishing in 9th/10th place.
|Episode||Theme||Song choice||Original artist||Order #||Result|
|Audition||Auditioner's Choice||"The House of the Rising Sun"||Animals||N/A||Advanced|
|Hollywood Round, Lines of Ten||A Capella||Not Aired||-||N/A||Advanced|
|Hollywood Round, Group Round||Group Performance||Not Aired||-||N/A||Advanced|
|Hollywood Round, Solo Round||Solo||"One Night Only"||Dreamgirls||N/A||Advanced|
|Showcase Week||Personal Choice||"I Still Believe"||Brenda K. Starr||N/A||Advanced|
|Top 24||Contestant's Choice & Idol Duets||"I Put a Spell on You'"||Jay Hawkins||7||Advanced|
|Duet "Beautiful Life" with Nick Fradiani||Nick Fradiani||8|
|Top 14||Favorite Moment||"I Put a Spell on You"||Jay Hawkins||2||Advanced|
|Top 10||Contestant's Choice||"Listen"||Beyonce||2||Eliminated|
|Trent Harmon ·La'Porsha Renae ·Dalton Rapattoni ·MacKenzie Bourg ·Sonika Vaid ·Tristan McIntosh ·Lee Jean ·Avalon Young ·Gianna Isabella ·Olivia Rox|