The original classic union of Crosby, Stills & Nash (& Young) lasted but twenty months. Yet their songs are lightning rods embedded in our DNA, starting with Nash’s “Marrakesh Express,” “Pre-Road Downs” and “Lady Of the Island,” from the first Crosby, Stills & Nash LP (1969). On CSNY’s Déjà Vu (1970), Nash’s “Teach Your Children” and “Our House” beseeched us to hold love tightly, to fend off the madness that was on its way. Nash is also known for his work as an activist; he used his music to raise awareness for Occupy Wallstreet, anti-nucleair energy groups and many more.