Biggest sound changes between albums

I definitely don't mean it like that! King Crimson and David Bowie are some of my favorite musicians and they change more than almost anyone! Honestly I'd much rather listen to King Crimson in the 90s or 2000s then any band who tried to stick to the same sound.

The OP does not condemn anything or anyone. 

Sometimes bands/artists change their sound, for the better or worse (they create something that is poorly received by their audience, sell-out or go with a trend, or more often than not create something uninspired). 

This is a scary OP and theme for me. It feels like we're saying that bands/folks can not change with the times and their music, and do something they want, rather than have to "sound" like they did the previous album, as it seems to be the issue here ... wanting the band to sound "the same".

For me, it's like we have ignored the history of the arts in the 20th century where CHANGES is what it was all about, be it because of a war, or simply a reactionary thing. And here we are, as if we do not allow a band to create something different ... because it isn't our preferred mode or idea.

No one has suggested that, as far as I can tell, which is easier to handle, but, again, I really think that an artist needs the freedom to do what they are capable of doing, and that means that changing, should be allowed ... and expected!

Many of the bands listed changed, and I consider many of them good changes, although I did not specifically think one band changed for the better or the worse, though I think that Hawkwind going back to the better known writer, took away a lot of really nice things that the band had been doing, and ASAM is a fantastic album, with the 2 very special long cuts on side 1 of the album. And breaking it all "back" seemed strange and I did not exactly think their next album was better ... to my ears, it sort of became very cartoonish all of a sudden, and Hawkwind, was NOT a cartoon band for me. So, yeah, that change was nuts.

Other changes were more natural ... GONG is an example, and perhaps looking for a new identity. Mike Oldfield, was probably under the need to get an album that sold, as if Incantations was too big and not something fans loved ... I, personally, think its one of his best albums.

PF is not much of a change. Animals was vastly different from how the band had been playing the 2 pieces from "Animals" which showed that RW was now in control, and changed the pieces into something else. Previously "You Gotta Be Crazy" was a very "space rock" thing, but folks here seem to appreciate the redo, and not the original. The redo was very obvious a RW thing! Both Mahavishnu and RtF had what I consider natural changes. Steve Hillage's changes were tough for me, as I liked his previous albums and excellent rock music, but it was obvious that he was changing to something else.

Again, other than PF, I kinda think that most changes were just fine for me, though I had already fallen off MO, for example, at the time, and I really didn't care for what Hawkwind did for years, until Electric Tepee when they became an Ambient Acid Rock band, and that album had the appeal and attack that Space Ritual did some 20 years before ... but sadly it is not heard, and it really makes "metal" sound like crap! It is that hard, and their next album had excellent things as well, as they extended the ambient thing. But the continuous redoing and re-releases of a lot of their early stuff, kinda ended Hawkwind for me. The Moody Blues I had already fallen out of it, before I even got to European stuff in 1972 ... the band had become a joke, and it wasn't neat poetry anymore, it was about being hip and cool now, and the music lost a lot of its meaning for me. Steve Hackett was a come down, in my book after the first album, as soon as he figured out that some fans wanted songs ... ciao baby ... there was better music all over Europe!

Electronic  to mainly acoustic/orchestral sound excepting Fanfare For The Common Man which apparently was only put on the album due to record company pressure but that was still a bit oddball.

Yes: Keys to Ascension 1 and 2 (1996-1997) to Open Your Eyes (1997) ...?

agreed... I simply can't get my head around the minimalism of IC. Attempting to find a tonal connection between each note played causes both my brain cells to short circuit at the same time...