...I don't care for labels/names like "Prog" to define music styles or influences, but-that's the world we live and communicate in.
Procol Harum
Zappa (Hot Rats)
Colosseum
Sgt. Pepper /Magical Mystery Tour
Traffic
The Zombies
Aside from these mid-late '60's bands or
albums, the usual suspects such as The Nice
would have to be credited (or blamed)...