Known neither as a spotlight-grabbing solo artist nor as the figurehead of the Roots, Black Thought is nonetheless widely recognized as one of the most skilled, incisive, and prolific rappers of his time, dating back to the '90s with Organix (1993), his group's recorded debut. Despite Thought's anchoring of a dozen studio albums with the Roots, including the Top Ten, Grammy-nominated releases Things Fall Apart (1999), Game Theory (2006), and How I Got Over (2010), demand for true spotlight-seizing projects has been high since the rapper scrapped an early-2000s solo project for...