The presence of bass beauty Esperanza Spalding in tenor-sax veteran Joe Lovano?s new Us Five ensemble is just one sign the quintet has the fire of youth in its belly. (Another is Havana-bred drummer Francisco Mela.) On Bird Songs, Us Five revisit the snaky music of bebop icon Charlie ”Bird” Parker (”Ko Ko,” ”Donna Lee”), but the vintage tunes inspire riskier improvs from Lovano, even when his rhythm section adheres to more straight-edged accompaniment. B+