The polite, impeccably dressed 21-year-old British songstress released her sophomore album in January to fawning reviews and impressive sales that forced the glitzy world of pop music to put down its laptops and take notice. 21 is a pained breakup album with lyrics so honest — "I had hoped that you'd see my face and be reminded ... it isn't over," Adele admits at one point — that it ranks alongside Fleetwood Mac's Rumours as one of the greatest lovesick records of all time. Adele expresses her sorrow (and occasional wrath) with a voice so nuanced that it can switch from light and sweet to raw and booming with just one note. 21 has gone on to sell over 13 million copies worldwide, making it the top-selling record in the world in 2011. (By comparison, Lady Gaga's Born This Way has sold only 8 million.) But even more impressive is the fact that Adele's song "Someone like You" is the first No. 1 single in U.S. chart history to feature nothing but a singer and a piano. Ever. No wonder Adele has joined the ranks of the few who need only go by one name.