Who sits atop the diva food chain? Why, Lady Gaga, of course. Gaga raked in $90 million in income in 2011, pushing her to the No. 1 slot on Forbes top earning women in music list.

Taylor Swift was closest to Gaga in the standings, but she barely even nipped at Gaga's stiletto heels, as the Mother Monster, who claims not to care about money, raked in double the amount Swift's haul. Swift netted around $45 million, courtesy of the mega mainstream success of 'Speak Now,' her Wonderstruck perfume, her CoverGirl contract and touring. Katy Perry, who also has her own perfume line and toured her butt off, placed behind Swift with $44 million.

The top 5 was rounded out by Beyonce, who saw a dip in her figures due to hardly any touring. However, the release of '4,' her House of Dereon line and her duo of fragrances allowed her to place fourth. She was followed by Rihanna, who pulled in $29 million, which includes revenue from 'Loud,' touring and her CoverGirl endorsement.

Judging from these figures, being a pop star is big business, which are based on pre-tax income from a variety of revenue streams, such as record sales, touring and more.