It's been a long time since I rock-and-rolled
It's been a long time since I did 'The Stroll'
Born out of a jam session during the writing of "IV", Rock and Roll is a tribute to the music of the late 50's and early 60's, which was inspired by blues and in turn provides the basis for most of Led Zep's work.
Itself is an archetypal rock'n'roll number. It's a twelve-bar blues in A major, and makes reference to many of the genre's hits and standards.
This line references "The Stroll", a dance of the rock'n'roll era that was popularised by The Diamonds in 1957.