All of the music for Cannabis was composed .
All of the music for Cannabis was written by Gainsbourg after the film had been shot , with help from arranger Jean - Claude Vannier , with whom Gainsbourg would again collaborate the following year on Histoire de Melody Nelson .
All of the music for Cannabis was composed and written by Gainsbourg after the film had been shot , with help from arranger Jean - Claude Vannier , with whom Gainsbourg would again collaborate the following year on Histoire de Melody Nelson .