They had started to play with a new formula for their writing, one that would truly take hold in their next album: they jam together, now aided by a drum machine to free up Phil Collins to use his voice as an instrument. Sometimes this produced great lyrics...other times you get "Whodunnit", a bizarre experiment featuring repetitive lyrics designed not to tell a story, but to be an instrument on their own, with generally annoying results. But this was the only real clunker on the album. They would begin to experiment in different ways musically, bringing in the Earth, Wind & Fire Horns to play on the single "No Reply At All", a song that many feel shows the true influence of Collins, as EW&F were favorites of his, and the band never really had guest musicians on their studio albums.
But they also had the Banks-penned "Me & Sarah Jane", musically a classic Genesis song in that it has several tone changes, and a very different structure than most of the popular music of the time, no real chorus, just a musical build with a dramatic climax, and a a soft drum machine to lead the listener out.
The lead track, named for the chord structure a-b-a-c-a-b is a great example of the new mixing with old. It is one of the longer songs, with half of the length being a true progressive instrumental exploration that gave all members a chance to shine. This part was cut off for release as a single, to the chagrin of many fans. They'd see this again on the next album with "Home By The Sea/Second Home By The Sea"...radio stations do not like longer songs, to get airplay they need to trim them to a more consumable length. Hopefully, the taste the listener gets on the radio draws them to buy the album and get the full experience.
Another excellent progressive song is "Dodo/Lurker", perhaps the monsters fighting back against Banks. His keyboard skills really shine in this track, at times taking on the form of a creature's cries. The tonal shifts here are exciting, and in true Genesis form, the music tells as much of a story as the lyrics do.
One of the real hidden gems of this album is "Like It Or Not", a gorgeous song with beautiful harmonies that really trump any of the pop songs of the day. Along with "Man On The Corner", these are the songs that start to feel more like a Collins project and less like a progressive album, but this results in some truly beautiful songs.
Maybe "Abacab" starts to stray from the prog rock roots that Genesis spent a dozen years establishing, but not so far that they couldn't still create some excellent progressive songs showcasing the musical talents of all three members. Perhaps this was a transitional album, but the transition is flawless, and signals that the members are so talented, they will make some great songs no matter what style they happen to be using.