Madonna has enlisted Katy Perry to help curate her art project.
The singer has chosen her fellow pop rival to act as guest curator for Art for Freedom, her online public art initiative that allows artists to submit videos, music, poetry and photographs on the subject of freedom.
Katy commented: ''I am so fortunate to have the freedom to express myself through music. Now I'm calling all of my incredibly creative KatyCats to use their talent to show Madonna and me how they express their freedom.
''I believe that 2014 can be a year of great social change. Together we can all stand up for Human Rights. Join the conversation, and let your art be your voice.''
The 'Roar' hitmaker is tasked with choosing a star artist, who will be awarded a $10,000 grant to help a non-profit organisation of their choice.
Magician and illusionist David Blaine was last month's guest curator of Art for Freedom, which was initially launched in September 2013.
Madonna said: ''Art can change the world, but first it needs to be seen and heard. Katy Perry and I are asking you to be that voice and show us how you define freedom in 2014.
''This will be a year of monumental changes for human rights, and we want you to be a part of that change. Let us hear from you.''