After several years of touring together and a new joint charity single, Chicago and Earth, Wind & Fire are contemplating a full-scale collaborative album project.

In conjunction with their 2009 summer tour, which kicks off June 5 in Orange Beach, Ala., the two groups put together a special set of songs for download, with proceeds going to World Hunger Year. Chicago recorded a version of EWF's 'I Can't Let You Go,' while EWF covered Chicago's 'Wishing You Were Here.' The two bands then collaborated on a new EWF-composed song called 'You.'

Chicago and EWF are asking fans coming to the shows to bring three cans of non-perishable food or $3 -- which will go to local food banks -- in exchange for a download card. The songs can also be accessed by making a donation at EWFandChicago.com.