Key work on the traditional ballad was undertaken in the late 19th century in Denmark by Svend Grundtvig and for England and Scotland by the Harvard professor Francis James Child. They attempted to record and classify all the known ballads and variants in their chosen regions.
Gaslighting is a form of manipulation that seeks to sow seeds of doubt in a targeted individual or members of a group, hoping to make targets question their own memory, perception, and sanity. Using persistent denial, misdirection, contradiction, and lying, it attempts to destabilize the target and delegitimize the target's belief.
gaslight unknown To manipulate events and situations in order to make a person believe that he or she is crazy. From the 1944 movie with Charles Boyer and Ingrid Bergman.