I was curious to see what music they included. This passage from the Wikipedia page made me smile:
> The inclusion of Berry's "Johnny B. Goode" was controversial, with some claiming that rock music was "adolescent", to which Sagan replied, "There are a lot of adolescents on the planet."
> The inclusion of Berry's "Johnny B. Goode" was controversial, with some claiming that rock music was "adolescent", to which Sagan replied, "There are a lot of adolescents on the planet."