I have recently purchased the Led Zeppelin complete studio recordings at around USD40! What a mega bargain for the music in the 10 CDs.
I have read some TBers recommend that someone hoping to get into LZ or JPJ should probably get the first 4 albums first (was that Bruce? can't recall), and I have read in reviews talking about the
"(d)evolution of led zeppelin over the 10 recordings", well, its interesting that the review added the probably "d" in the word evolution, probably meaning that some people might not like the later studio recordings as much as the first few?
I have listened to almost all of their albums, giving each 10 spins at least before I wrote this. And I am here looking for a listening guide on the musical side of the 10 albums.
I personally find that the first 4 are more standard rock/blues tunes, catchy, some even pop-style. The last few albums, some are particularly hard to like, some take more than 10 listens before realizing the punch of it, and some sounds so sophisticated (Crunge for example).
Any comments/reviews/what-to-listen-for on the 10 albums will be of great help to my future listening.

