The name David Zychek is likely not a familiar one to the world at large. For denizens of the Central Texas music scene, however—especially those who were around from the seventies to the nineties and even beyond—Zychek is synonymous with raucous electric guitar. And though the rock and roll hero died a mostly unsung legend of the genre eight years ago at the age of 64, a new documentary film by two fellow Wacoans aims to ensure that his legacy will live on.Z: The Story of David Zychek, by Anna and Troy Shaw, offers a celebration of Zychek’s life by shining a deserving spotlight on the virtuosic talents he possessed with the guitar, but also by giving a nod to his lasting impact on the…