666 by Aphrodite´s Child. An experimental prog psych etchin fusion epic. Having heard this unbelievable work it´s no wonder why Jon Anderson praised this masterpiece whereas many prog musicians and fans, like one beeing my ELP buddy, just ignored the talent and even hated the band only because of Demis Roussos´ voice that actually is unique with the high vibrato, and is one of the most beautiful male voices in rock´s history. His work is sublime, not to mention Irene Papas´ vocal acrobatics on "Infinity", she´s just another misunderstood unsung hero of the prog era, not even being considered a prog singer/artist in the first place. After departure of Rick Wakeman, Anderson did ask Vangelis to join his band but, well unfortunately or luckily depending on one´s opinion Vangelis refused.
A word of Yes, praised by many as the best prog band, well to me not greatest not even close but their work is quite versatile, from the late 1960´s period to the end of the Wakeman era. Luckily Yes had already made their ultimate work, The Oceans. As for Yes repertoire I prefer the early work Banks/Kaye era for their more psychedelic style/sound with Hammond organ and Bank´s guitar work, musically it´s more interesting and lively and at places as versatile as the Wakeman era symphonic prog, IMO. And Wakeman made triumphant return in late 1970´s culminating in another masterpiece, Tormato in the middle of the dull new wave, the band still experimenting with new sounds and still with great attitude and approach to rock´n´roll and prog rock when major prog acts maybe excepting King Crimson descended into lame pop music. And it was the last great prog and rock album from the incredibly versatile 1970´s, the most ignored and therefore unknown and again sadly hated, at least.
And luckily both Area and Banco did their (minor) masterpieces in the last years of the 1970s, but the Italian scene is a completely different story to be told...