It's from the album 'A Year Without Rain' by Selena Gomez & The Scene.
Buy here: itunes.apple.com/us/album/a-year-without-rain/id391779019
There is no pitch change , it is slowed down to avoid copyright issues.
This is for educational and entertainment purposes only.
And before anyone says anything I know there is loads of spelling mistakes, I'm sorry I made this when i was quite young ;)