Diane Warren

Self

Cher

Self

Gloria Estefan

Self

Jerry Bruckheimer

Self

Jennifer Hudson

Self

Randy Jackson

Self

Clive Davis

Self

Kesha

Self

David Foster

Self

LeAnn Rimes

Self

Len Chandler

Self

Kathrine Narducci

Self

Toni Braxton

Self

Crystal Lujan

Self

Jack White

Self

Kathy Nelson

Self

Eric Vetro

Self

Bonnie Greenberg

Self

Paloma Faith

Self

Paul Stanley

Self

Common

Self

Céline Dion

Self (archive footage)

Madonna

Self (archive footage)

Quincy Jones

Self (archive footage)

Beyoncé

Self (archive footage)

Sofia Carson

Self (archive footage)

Becky G

Self (archive footage)

Jon Batiste

Self (archive footage)

Gwen Stefani

Self (archive footage)

Blanco Brown

Self (archive footage)

Jennifer Lopez

Self (archive footage)

Liza Minnelli

Self (archive footage)

Lady Gaga

Self (archive footage)