"Bubbly" is the debut single by American recording artist Colbie Caillat from her debut album, Coco (2007). Written by Caillat and Jason Reeves and produced by Mikal Blue, the song was released as the albums lead single in May 2007. It remains Caillats biggest hit in the US to date, and her only single to reach the top ten of the Billboard Hot 100. The singles music video, directed by Liz Friedlander, aired on MTV, VH1 and CMT. A still from the music video was used as the cover for Caillats debut album, Coco. The video/single is also featured in the hit PlayStation 2 karaoke game SingStar Pop Vol 2, released in late September 2008 in the United States. It was also featured in SingStar Hottest Hits in PAL regions. "Bubbly" was written by Colbie Caillat and Jason Reeves. It is an alternative pop song, folk song, and acoustic song. "Bubbly" is written in the key of A and primarily features a gentle guitar instrumentation which uses a capo of 7th fret. The guitar uses open D tuning (low to high): D-A-D-F?-A-D.