'Ramble On' (1969)
The song where Plant first nails his mystic-storyteller alter ego combines familiar folk-blues concerns – hitting the road, looking for a woman – with a riff on J.R.R. Tolkien's The Lord of the Rings. It starts with Page's acoustic strumming and Bonham patting out a rhythm (probably on his knees, possibly on a guitar case or a drum stool; no one seems to recall). Then the chorus crashes in and Page switches on, flinging knife-edge licks while Plant turns from a Hobbit back into a sex machine.