Led Zeppelin: Flowering Jimbert, Royal Albert Hall, June 29, 1969
From a review in New Musical Express:
In one way, they appear to be fighting each other for dominance, in another they become as one but in the final analysis they serve to haul each other onto greater and greater heights. Plant, with shoulder length blond curls, employs his voice as a fourth instrument. Page, a contrast with shoulder length black hair, evens the score by using his instrument as an extra voice. The result at low key is fascinating; at its high devastating.