6-year-old Olivia Ajero plays this jazzy piano arrangement of "Santa Claus Is Comin' To Town" by Phillip Keveren from "More Christmas Piano Solos for All Piano Methods Level 4" from the Hal Leonard Student Piano Library. She is playing with the digital audio accompaniment that comes from the enhanced CD that comes with the book: http://www.sheetmusicplus.com/title/more-christmas-piano-solos-level-4-sheet-music/19496242?aff_id=198335
The iPad app that she is using is AnyTune Pro+:
http://www.anytune.us