A return to form after the last two albums, which were a bit too romantic, soft, and atmospheric for my taste. Ironically, Duke is more "commercialized" than either of them, but mainly because Collins was turning into a (good) singer-songwriter and had contributed pop tracks like Misunderstanding. There's still quite a lot of prog to go around on this album; I would argue that this album is slightly more prog than pop, whereas the previous two albums were 50/50. The first three songs are a nice pseudo-prog battery, while the finale of Duke's Travels/Duke's End shows that Genesis were still holding on to their roots.

Turn it On Again is a solid, catchy rocker...for what it's worth.

This album has the cohesive feel of a prog rock concept album without actual being one. All the songs flow nicely together. It makes for another good "autumn record" (as were "...ant then there were three" and "wind and wuthering"). The instrumentation is often contemplative and building, engrossing even without tales told in narratives like the two duke songs, "duchess", "heathaze" and "man of our times". The hits you would know are maybe "man of our times", "misunderstanding", "turn it on again" and maybe "behind the lines" (reprised by phil collins solo). Check out the pained sadness on "guide vocal" which has one of my all-time favorite common truth lyrics, lifted and summarized from a previous genesis album, "you kill what you fear", or check out bitterly reflected futility of "man of our times" where the only levity comes from a high-pitched synth segment. i love how some of the songs segue into each other, especially the first 3 tracks and the duke suite. A number of songs, like "man of our times", "duchess" and the duke suite sound epic without really being epic statements as "firth of fifth" or "the return of the giant hogweed" were. More understated than abacab, i prefer duke's subtleties more...barely.

Duchess was the best track

Until this album Genesis music broadly followed mythological themes, even after Peter Gabriel's departure, A trick of the Tail adhered to this ethos... but this album stands alone in their catalogue (at least to me) in that it marks a sea change in their thinking. Not quite yet the pop driven work of the albums that followed, although it's 'geneisis' is here, it still contains a hint of the progressive earlier work in the writing and playing, if not necessarily in the instruments used. As here they begin to mix the emerging synthesiser technology with traditional instruments, creating a unique blend of the two, but the synths are used sparsely and just for colour and shading.
In fact if Duchess is taken along with Phil Collins solo In the Air Tonight, a strong similarity in method and execution can be felt, and the minimal approach to the use of the technology makes for a striong, timeless, and distinctive sound, perhaps among the finest examples of the use of technology from the time.
Duke is a complete work on a unified theme, but this time concerned with the story of the eponymous character and his 'Duchess'... I think you could almost take it as an album version of 'Don't you want Me' by the Human League- The Mogul and the unsypathetic Singer (Could almost serve as a warning to Simon Cowell!)... or is he a stalker who imagines this connection to the singer? the ambiguity allows for both readings i think.
Shorter, more punchy songs than much of their earlier work, but retaining the style... but some of the most memorable tunes they've done with great musical phrases, hooks and melodies.
Deserves to be regarded as good an album genesis ever produced