GrassMarijuana is the most controversial drug of the twentieth century. Smoked by generations of musicians, students and workers to little discernible ill effect, it continues to be reviled by the vast majority of governments around the world.

With his new film, Grass, veteran filmer Ron Mann brings his impeccable historical facility and story telling skills to recount how a relatively harmless drug has been demonized for decades.

With a rueful yet incisive script, deft editing and an impressive soundtrack featuring original songs by Mark Mothersbaugh and a veritable potpourri of tunes ranging from the Swing Era's "Reefer Man" through Dylan's "Rainy Day Women" to the hippie lament "One Toke Over The Line," Ron Mann's Grass boasts extraordinary production values.

Funny yet political, Grass charts the terrible loss in imprisoned lives and billions of dollars wasted fighting a drug that refuses to go away.

Watch the full documentary now