Groep 1850 (Group 1850) started life in the Hague as Klits (from clitoris). They soon changed their name, made several underground records between 1965 and 1971. Their single "Look Around"/"Misty Night" (on the Yep label from 1966) is a real collector's item, as is their second Lp called "Paradise Now". In 1967 Groep 1850 supported the Mothers Of Invention with their Dutch concert in the Amsterdam Concertgebouw.
These are photos from concerts where Groep 1850 played, so they may be of other bands that played the concert as well.
Janis Joplin / Groep 1850 / Brainbox Apr 11, 1969 Amsterdam, North Holland, Netherlands Uploaded by Zimtrim