At the heart of Esperanza Spalding's new album, Songwrights Apothecary Lab (S.A.L.), is a question: "What do you need a song for?" In pursuit of answers, Spalding, a Grammy-winning jazz singer and bassist, assembled a team of more than just other musicians; she created a laboratory of sorts, gathering neuroscientists, psychologists, ethnomusicologists and more. "We are like shipwrights," Spalding says in an interview with NPR's Ailsa Chang. "We build things.