The original key of the song Bubbly by Colbie Caillat is A major. It was released in 2007 as the lead single from her debut album "Coco." The song was written by Colbie Caillat and Jason Reeves. A fun fact about the song is that it was inspired by Caillat's experience of falling in love while at the beach. The melody of the song is soft and cheerful, with acoustic guitar and light percussion creating a relaxed and romantic atmosphere.