The Penguin guide points out that Kind of Blue was the first widely acknowledged example of 'modal jazz.' The music must have seemed strikingly new when it was released, but looking back on it now every note seems familiar and right where it should be. As the Penguin Guide puts it, Miles' innovation has been thoroughly absorbed.
The only surprise in the personnel Miles chose for KOB was alto sax player Julian Cannonball Adderley. Adderley was a music teacher who was persuaded to try professional music. It worked. He played with Miles between 1957 and 59. It was Miles who inadvertently gave Julian his nickname. He called him "cannibal" Adderley. Julian was a big fellow, and I gather he would eat a lot of food at one sitting. A reporter misheard it, fortunately. Cannonball is a great nickname for this great musician.
About a year before KOB, Adderley recorded an album as leader, with Miles in the unusual role of sideman. There is some doubt about who was really in charge. We do hear Miles say, at the end of 'One for Daddy-O': "was that what you wanted, Alfred." He would be speaking to Producer Alfred Lion. I don't know enough to have an opinion, but Somethin' Else is a magficient recording, maybe one of the ten best in era.
Who was in charge may matter a great deal, because I think that the mood and motion of KOB is first evidence on this Adderley issue. Everyone remembers the first track, 'Autumn Leaves," but the title track is most evocative. Here it is. Give it a listen, and then compare it to KOB.
Cannonball Adderley/Somethin' Else/Somethin' ElseI think you find that Miles' horn sounds pretty much the same on both discs.