21

 21 is her second album. It was released on 24 January 2011 in Europe and on 22 February 2011 in North America by 

XLRecordings and Columbia Records. The album was named after the age of the singer during its production. Composed in the aftermath of the singer's separation from her then partner, the album typifies the near dormant tradition of the confessional singer-songwriter in its exploration of heartbreak, introspection, and forgiveness.

Adele began writing 21 in April 2009, when still involved in the relationship that subsequently inspired the record. Dissatisfied with once again portraying herself as the musical tragedian of her debut, she had intended to compose a more upbeat and contemporary follow-up. However, studio sessions ended prematurely due to a lack of inspiration. She resumed production immediately after the breakdown of her relationship, channelling her heartbreak and depression into her songs. Praised by critics for its understated production, vintage aesthetic, and Adele's vocal performance. Five singles were released to promote the album, with "Rolling in the Deep," "Someone like You" and "Set Fire to the Rain" becoming international number-one songs, while "Rumour Has It" charted in the top 20 across Europe and North America. 21 was the biggest selling musical release of both 2011 and 2012 and helped revitalise the lagging sales of the UK and US music industry. With sales of over 31 million copies worldwide, it is the best-selling album of the 21st century, and one of the best-selling albums of all time. Shortlisted for the 2011 Mercury Prize, 21 won the 2012 Grammy Award for Album of the Year and the Brit Award for British Album of the Year.