They did give credit for Nobody's Fault But Mine, and eventually for all of the other ones for which they failed to do so at the beginning. I'm fairly sure Willie Dixon was credited from the start though, although maybe that's just on the new album releases.
But as you said, that's what blues have always been about anyway. They learn off each other and work on each other's songs. 'Ripping off' is a completely idiotic way to put it.
No offense to you Ismene, I just don't like people criticising Zep :D
No offence taken Pagey! I think there is something a bit shady about some of the zep stuff - it wasn't even just old public domain blues songs. For instance, see if this guitar lick from 1961 rings any bells!!
http://www.youtube.com/watch?v=TvtabNAb_wE
Nice guitar playing on stairway pagey btw!


their guitar playing