Forbes top-earning musician of 2015
Forbes compiled their list by examining the pre-tax income from June 2014-June 2015 from concerts, record sales, publishing, endorsements, and other business ventures
http://www.dailymail.co.uk/tvshowbiz/article-3351216/Ka-ching-Katy-Perry-conquers-rival-Taylor-Swift-earning-musician-2015.html