"Once Upon a Time" is an instrumental song featured in Steven Universe: The Movie, when White Diamond reads the story of how Pink Diamond relocated on Earth to become Rose Quartz, gave birth to Steven, and the birth of Era 3 thanks to Steven's efforts of peace.
- Music by Jeff Ball.
- Flute, Oboe, English Horn performed by Kristin Naigus.
- French Horn performed by Marc Papeghin.
- Harp performed by Joanne Moo.
- Violin, viola performed by Jeff Ball, Michaela Nachtigall, and Patti Rudisill.
- Cello performed by Michael Evans.
- Contrabass performed by Travis Kindred.