Upright-bass prodigy Esperanza Spalding was barely out of her teens when she dropped her first CD, Junjo, a stunningly sophisticated yet playful set of acoustic trio jazz: rubbery bass, piano, drums and sexy Latin melodies harking back to the Seventies Brazilian jazz of Flora Purim. For her second disc, 2008’s Esperanza, she added hints of funk and hip-hop. Chamber Music Society finds Spalding stretching herself a bit too thin, pulling together everything from a Broadway-like duet (“Apple Blossom,” with Milton Nascimento) to scat-heavy, string-and-percussion excursions (“Chacerera”). But her talent is undeniable. The chamber setting provides a feathery pillow for moody tracks like “Little Fly,” William Blake’s poem set to lovely bass and strings.