How did that one stump you Tote...? I recall "Houses of the Holy" was almost a departure from Led Zep previous LP's, while Physical Graffiti seemed to cement them in their previous form of infamy, even tho' the bastages, did some basic old blues refinements, or as some have claimed, utter Plagiarism, tho' I don't necessarily see them as plagiarist, only taking an old tune, & growing from perhaps a simple melody, then adding all kinds of bells and whistles on a soap box cart, turning it into a Go-Kart...