The Funk Jam is a pseudo song created to describe a funky section of Whole Lotta Love usually right after the the first vocal section and before the medley songs. It first appeared during the European tour in the spring of 73 and contained the pseudo song of Theremin Duel. It was played all through out 73 and then again during the second leg of the US tour in 75 and Earls Court. It also was played at a number of shows on their final tour in the summer of 1980.
The section was inspired by James Brown with the funk bass and the percussive guitar playing. Plant often sang short bursts of James Brown lyrics from songs like 'Cold Sweat', 'Sex Machine', 'Licking Stick'.
In 75, when the performance of Whole Lotta Love was truncated down and the medley section was largely cut out, the Funk Jam and Theriman Duel provided the only real vehicle for imrpovisation within the song.