Goodbye Lullaby is the fourth studio album by Canadian singer-songwriter Avril Lavigne, released worldwide on 2 March 2011 through RCA Records. Recording sessions for the album began in November 2008 and continued over a period of nearly two years, concluding in October 2010. Goodbye Lullaby is primarily a pop rock and pop album, more introspective than Lavigne's previous material. It consists mainly of stripped down instruments such as the piano and acoustic guitar. Lavigne assumed an integral role in the album's production, co-writing every original, as well as collaborating with several producers including Max Martin, Shellback, Butch Walker, and her ex-husband Deryck Whibley. Goodbye Lullaby is Lavigne's third and final studio album with RCA, following The Best Damn Thing (2007) and Under My Skin (2004).