The groove on vinyl records, particularly the old 78s rpm jazz records of the 20s and 30s. The depth and width of the groove indicated the speed and beat - something later picked up by early rappers like Grandmaster Flash. Jazz musicians used 'groove' as a term of appreciation and this later became part of pop music culture - the Beatles were famously fond of the adjective groovy.Much later 'groovy' became one of the catch-phrases Austen Powers, a sign that the word had come to symobolise 1960s fantasies of personal liberation and free love.