I don't know, I think they always had an ocean of potion locomotion.

Poppagator, right on the money! Sure there was a very significant psychedelic component to the Dead, but their grounding in folk, bluegrass, and country traditional music was always evident. They were definite proponents of the so-called "Folk Process" to the point of taking traditional music and intentionally adding verses or re-working entire melodies to create something new with an old flavor, take Casey Jones, Tennessee Jed, and Dupree's Diamond Blues as examples. Those who condemn the Grateful Dead based on freeform electric jams like New Potato Caboose and because of their legion of Deadhead followers are overlooking a prime doorway that admits fans of pop and rock n roll into the world of traditional music.