The missing link between post-war R&B and the raucous roar of rock 'n' roll, jump blues bopped into being in the '40s as the increasingly accelerated pace of American life demanded something with more momentum. The hard-swinging grooves of tunes like Louis Jordan's "Choo Choo Ch'Boogie" were sensual, bouncy, and ideal for getting on the good foot. And by the time Big Joe Turner unleashed the force of nature that is "Shake, Rattle and Roll," he was laying down a blueprint that would be picked up by the first rock 'n' rollers mere months later.