Thank you, gracias, merci Bello Pubico for having found those videos of Chapi Chapo online. Chapi Chapo was an animated series created for French television in 1974. They were my absolute favourites when i was a kid. I never fully understood the plot but the hallucinating music was driving me wild.
Related: La Linea; Bibi has posted a series of links to Felix The Cat videos: part 1 and part 2.