Floyd's Animals is truly a full album-length "novel" with a nearly "classical" level of compositional complexity, sensitivity and skill... themes recur throughout and are musically related to each other and reprise in touching and devastating summing-up in the end like a great symphony. Led Zep is more gut-level intensity and more raw, very awesome, but never did this sort of totally integrated rock-symphony (The Wall is cool, but more like an opera with lots of various bits and pieces thrown in... much less of a continuous-flow symphony)