Agree Robin Trower's album track Daydream off the Twice Removed From Yesterday album from 1973 is awesome!.
Would Rainbow's Catch The Rainbow off Ritchie Blackmore's Rainbow album from 1975 be a contender?.
Also the album track Leaf And Stream off the Wishbone Ash album Pilgrimage from 1971 would that be a contender as a folk/rock ballad?.