According to Jimmy Page, the next Led Zepp album would have been a return to hard rock rather than all synthesizers and over-production.
http://en.wikipedia.org/wiki/In_Through_the_Out_Door
I think they definitely had at least a couple more albums in them, whoo know maybe they would have gone against the grain of 80s music and kept rock n roll alive through that dreary decade.
If
Ozone Baby and
Wearing and Tearing are any indicators, I think the next album would have featured both tracks and would have been a return to their roots type of album.
They recorded
Ozone... and
Wearing... during the ITOD sessions but for whatever reasons, they were kept off the album in favor of lesser tracks.
Which reminds me of one of Zep's most annoying habits: Keeping great tracks off albums they were recorded for, then releasing them later, often times on albums where they seem a bit out of place. (Or, in the case of
Houses of The Holy...for God's Sake, IT WAS THE TITLE TRACK!!! HOW DO YOU KEEP THE TITLE TRACK OFF THE DAMN ALBUM?!))
The Rover and
Houses of The Holy were recorded during the Houses of The Holy sessions...and were kept off the album in favor of tracks like
The Crunge and
D'yer Mak'er were put on instead, go figure...
Traveling Riverside Blues: Recorded during the the period they were recording Led Zeppelin II...not used on that album, but that one I can see; it didn't even sound like Zeppelin III, let alone Zeppelin II.
Would have been a perfect fit on either
[Insert Your Preferred Name for Zep's Fourth Album Here] or Houses... though.
You can make arguments for a lot of their songs that either never got released on the original albums (
Hey, Hey, What Can I Do?, just another example) or were held off the albums they were recorded for.
Back to the topic at hand, I
do like to think that Plant could have written
In The Mood with Jimmy Page.
I mean, think about In The Mood and think about how great it would have sounded with Zep on the instruments.
Any rate, I take Page's word for it and say, harder Zep albums in the 80's, a few more albums and maybe semi-retirement by 1990 or so.