Yeah some serious prog rock styles would be good ..also from the darker end of the spectrum ..Van der Graaf Generator (1975-76) and King Crimson (73-74 vintage).
The german group 'Can' ('future days'- 1973)...the French band Magma.. ('Tristan et Iseulde' and 'Kohntarkhosz' from 1974.)..and of course the great 'Gentle Giant' from England who were one of Frank Zappa's favourite bands..
Alan