Vince Guaraldi was a minor pianist on the West Coast jazz circuit when 1962’s “Cast Your Fate to the Wind” crossed over to pop radio and won a Grammy. Still, almost anyone who knows his music probably knows it because of the work he did for the animated TV specials based on the Peanuts comics, which debuted in the mid-’60s with A Charlie Brown Christmas and have continued to define a particularly warm, funny image of American childhood for more than a half-century since. “Linus and Lucy” is the fulcrum (did you ever know the title?); “Charlie Brown Theme” is a close second—both sparkling, inspired pieces of melodic piano jazz arranged into small, poplike bites. The sweetness (and the joke) was projecting onto these little cartoon kids the same worries, triumphs, sorrows, and ego we expect from flesh-and-blood adults. And as simple as the music sounds, it achieved something rare—making jazz accessible to millions.