On January 13, 2009, Caillat also released a duet with Jason Mraz, called "Lucky", on his album, "We Sing, We Dance, We Steal Things". Caillat's second album, "Breakthrough", was released in August 2009. Most of the album was co-written by Jason Reeves and features guitarist David Becker on two tracks. Becker has worked with Caillat's father Ken. Caillat had writer's block during the recording sessions, so she enlisted her friends Kara DioGuardi and Jason Reeves, and they went to Hawaii for three weeks, rented a beach house and wrote songs. "Breakthrough" debuted at number-one on the US "Billboard" 200 chart, with first-week sales of 106,000 copies, becoming her first album to debut at the top and an improvement of the first week sales of her debut album "Coco" (2007), which started at number five with only 51,000 copies. It was also Universal Music Group's sixth consecutive number-one album to debut at the top. It was later certified gold by the Recording Industry Association of America (RIAA). The first single, "Fallin' for You", was released on June 29, 2009. The "lilting" mid-tempo ballad "features an instantly catchy chorus and toe tapping melody," as defined by Melinda Newman of HitFix. It achieved chart success in the United States, reaching number twelve on the Billboard Hot 100, her second highest charting single and her highest debut with 118,000 first-week downloads, spending fourteen weeks at number two on the Adult Pop Songs and topping the Adult Contemporary chart. Elsewhere, it reached the top-twenty in four other countries and top-forty in the remaining territories.