Esperanza Spalding contains multitudes. At her most creative, the charismatic artist doesn’t so much cross over from jazz to pop as she refracts genres into little slivers that play off each other. Once upon a time in the 20th century, her contemporary R&B effort “Radio Music Society,” released last year, would have prompted a surplus of critical angst over whether or not it’s really jazz. But today, in no small measure because the jazz world can really use a superstar of Spalding’s beaming appeal, it’s all fair play. Continue reading The Boston Globe.com.