A range of rock acts, from been-a-thing-forever Primus, still-a-huge thing Dave Matthews, to just-became-a-thing Alabama Shakes, have contributed songs to 'Turn the Tide,' a charity album released as companion to 'Last Call at the Oasis,' a documentary investigating the global water crisis. Grab the record here for a donation of at least $1, and watch a trailer of the film below. 

Dave Matthews offered up the ominously titled 'Dead and Done'; Primus gave the eco-apocalyptic 'Last Salmon Man'; My Morning Jacket supplied the hopeful 'The Day is Coming'; and Alabama Shakes provided the stomping 'Hold On.' The Whigs, Amos Lee, John Butler Trio, and other artists contributed to the download-only album as well.

Academy Award winner Jessica Yu directed 'Last Call at the Oasis,' released by ATO Pictures. By documenting problems with the global water system and the communities stricken by its effects, the film proposes that water scarcity will be the 21st century's defining issue. The universal solvent is in need of help -- let's hope rock 'n' roll can be its advocate.

Watch 'Last Call at the Oasis' Official Trailer