I went ahead and watched Heavy Metal (1981).
I went into it knowing it was an influence for some later stuff, and that there were some well known Canadian voices.
One caveat, I've not seen Love Death + Robots yet.
So, Heavy Metal was...interesting. The last short story was the best, imo. Also, it had the best animation. The rest were kind of lacking in substance and I forgot to pay close attention to the music because the animation and plots were meh. I think the music was good?