High Quality Content by WIKIPEDIA articles! The Billboard Adult Contemporary chart ranks the best-performing singles in that category in the United States. The first number one song of the year was claimed by Mariah Carey with "Oh Santa!", a position it also held for the last two weeks of December 2010, thus spending a total of four weeks atop the chart. American pop rock band Train topped the chart for three consecutive weeks with "Hey, Soul Sister". Bruno Mars topped the chart for 20 non-consecutive weeks with "Just the Way You Are". It also ranked at number one on the 2011 Adult Contemporary year end chart.Katy Perry's "Firework" peaked at number one for one week. It ranked at number two on the Adult Contemporary year end chart. Adele topped the chart for 19 consecutive weeks with "Rolling in the Deep", and for one week with "Someone Like You". "Rolling in the Deep" ranked at number three on the Adult Contemporary year end chart. The Band Perry topped the chart with their song "If...