Celebrity charity work has been around as long as showbiz itself.
In fact, according to Myrlia Purcell, founder of LooktotheStars.org, which tracks high-profile benefits, even Beethoven performed for charity.
Purcell and her staff have compiled a list of the most generous stars based on the number of nonprofit organisations and events they support. Some have their own foundations; others lend their name and fame to multiple causes.
"Nonprofits say having a celebrity involved can make or break their events," Purcell said.
Annie Lennox is considered #1. A U.N. Goodwill Ambassador fighting HIV and AIDS, the 57-year-old has made news with more than 200 nonprofit efforts in the past six years and supports 36 philanthropies.
Elton is next, supporting 45 charities, including his own namesake AIDS foundation, which funds 55 programs worldwide. Third is a former U.S. president. Bill Clinton, who is associated with 50 charities, also has his own organisation.
Bono, Brad Pitt, George Clooney and Angelina Jolie are among others who made the grade.