Led Zeppelin's version of a Willie Dixon classic.
Recorded at Royal Albert Hall in 1970.

 William James Dixon (July 1, 1915 – January 29, 1992) was an American blues musician, vocalist, songwriter, arranger and record producer. He was proficient in playing both the upright bass and the guitar, and sang with a distinctive voice, but he is perhaps best known as one of the most prolific songwriters of his time. Next to Muddy Waters, Dixon is recognized as the most influential person in shaping the post–World War II sound of the Chicago blues.