From where I'm sitting, The Lamb Lies Down on Broadway was the zenith of Genesis' greatness just like I see Yes's greatest peak at Close to the Edge.
I think by the time they had hit Lamb, they had gone where no man had gone before. Foxtrot and Selling England are insanely mesmerizing and the musicianship is at a ridiculous level! Same with Nursery Cryme.
When they delved into Lamb, they explored territory they had never hit before. It wasn't the charming pastoral themes and very English-sounding Genesis, but something more experimental, dark at times, a very motley and charming yet disturbing album. Lamb encapsulates everything that is good and breathtaking about Genesis for me. It has the humor in Counting out Time, the weirdness in Colony of Slippermen and mystery and awe in Anyway and Chamber of 32 Doors and Carpet Crawlers. It has this absolute badass punk sound in the opening track and Back in NYC. It has an unprecedented almost Kashmir blaring rocking sound in Fly on a Windshield. The album is a tapestry of perfection.
After this album, I very very much enjoy Wind & Wuthering as well as Trick o Tail, but for me after Peter departed, something wasn't there that I absolutely adored....the mysterious traveler! That element of mysticism, the unknown, the crackle in the voice, the weird mixture of beauty and angst.
And then there were Three, Duke, all that stuff for me was a massive downturn. I'm not one of those guys who hates Genesis in their more pop era, but for me songs like Duchess and Duke's Travels lose me. I think "Turn it On Again" is the best song on Duke by a mile, but in comparison to the glory of the mid 1970's, doesn't hold a candle. I listen to the pop era of Genesis regularly, especially songs like Abacab, etc. but for me the grandeur of who they were, the peak was the Peter era and the Lamb.
It's so sad they parted ways.....
Their history is so different from that of Yes, my other favorite band. There was no going back like there was with Yes. Yes was profoundly progressive like mad, then broke up, went pop in the 1980's with 90125, etc. but they then went back to their roots with albums like Magnification and Fly From Here, etc. Even Union was proggy at times. Yes went full circle back to their prog roots and in concert today they showcase almost none of the 80's pop.
Genesis is the opposite. They haven't returned to the prog days, just a medley of songs and bits and pieces amidst a primarily pop sound.
Sorry for my lack of brevity
Lamb----the heights of perfection