Demi Lovato, 'Give Your Heart a Break'
Demi Lovato is making a smooth transition from squeaky-clean Disney princess to grown-up pop star: her latest single is racing up the Hot 100.
See ResultsElton John and Kiki Dee, 'Don't Go Breaking My Heart'
In 1976, Elton John tried out a new musical direction with this Motown-influenced duet. It worked – the song went straight to Number One.