Madonna holds David Banda in her arms, in this April 19, 2007, file photo at Consol Homes, a day care center that she is funding in the village of Masekese, Malawi. [AP]

Madonna, one of the headliners at this summer's "Live Earth" concerts, released a new digital song for the musical event on Wednesday.

The global concert series, taking place July 7, is designed to raise awareness about climate issues. "Hey You," which Madonna produced with Pharrell Williams, doesn't specifically talk about earth issues, but the ballad's lyrics refer to loving and saving each other.

Madonna is scheduled to perform the song during the show at Wembley Stadium in London. Other shows will take place in Giants Stadium in East Rutherford, N.J.; Tokyo; Shanghai, China; Johannesburg, South Africa; Sydney, Australia; Rio de Janeiro, Brazil; Hamburg, Germany; and Istanbul, Turkey.

"Hey You" is available on MSN.com. The first million downloads are free, and Microsoft is pledging to donate 25 cents per download to the Alliance for Climate Protection.

Besides Madonna, other headliners slated for the London concert include the Hot Chili Peppers, Genesis and the Beastie Boys.