Lady GaGa and Elton John performed together at the Grammys earlier this year, and now they'll have the opportunity to collaborate once again.

Those pop stars, plus Sting and Shirley Bassey have signed on to a Rainforest Fund benefit concert to be held at Carnegie Hall on May 13. The conservationist organization was founded by the Police frontman and his wife Trudie Styler, and the event is in celebration in its 21st year of existence.

Styler told Billboard that GaGa is "such a great young woman," and that the latter will be taking a break from her European tour to help out. "Sting, Elton and Gaga will play together, and the boys will be performing with Dame Shirley, doing a great rendition of 'Hey Big Spender.'"

More special guests are expected to be announced. Tickets go up via Carnegie Hall in early April; more info is to be had at rainforestfoundationfund.org.