A group of "American Idol" winners from its 15-year history returned to the show's final season Thursday to sing with the first half of the last 24 contestants.

Ruben Studdard, Fantasia Barrino, Lauren Alaina, Nick Fradiani, Scotty McCreery and Caleb Johnson stepped up to the same "American Idol" stage which ushered in their fame in past years to harmonize with 12 current contestants.

Some notable performances included Fantasia's duet with contestant La'Porsha Renai.

The duo performed Ella Fitzgerald's "Summertime," and received positive feedback from judge Jennifer Lopez, who called the song "mindblowing."

Yahoo TV notes a sense of chemistry between "American Idol" alum Lauren Alaina and contestant Mackenzie Bourg.

The duo sang Lee Ann Womack's "I Hope You Dance," and showed signs of flirting before and after the song.

After the performances, Emily Brooke, James VII, Jenna Renae, Jordan Sasser and Stephany Negrete were sent home.

The next half of the 24 "Idol" contestants will show off their performances starting next week. Fox's "American Idol" airs Wednesdays and Thursdays at 8 p.m.