Solange and Beyonce perform together

R&B diva Beyonce and sister Solange Knowles have teamed up to perform in a one-off benefit show in Minneapolis next month to help two charities.
The "Put a Ring On It" hitmaker will be playing at the Target Center in Minneapolis on July 16 to benefit the Charles & Phyllis Newman Foundation and their own charitable institution, The Survivor Foundation.
She will be joined by sister Solanger as a special guest.
The concert tickets range from $39 to $1,000 and can be bought at the Target Center's Box Office and all Ticketmaster outlets.
The Newman Foundation is an organization that supports programs that support medical research and discovery in humans and animals. The Survivor Foundation provides assistance, education and support to survivors of social, economic and catastrophic hardships

Umm...if Solame is going share the same stage together what will they sing? Do they have a song together?