Herbie Hancock will always be one of the most revered and controversial figures in jazz -- just as his employer/mentor Miles Davis was when he was alive. Unlike Miles, who pressed ahead relentlessly and never looked back until near the very end, Hancock has cut a zigzagging forward path, shuttling between almost every development in electronic and acoustic jazz and R&B over the last third of the 20th century and into the 21st. Though grounded in Bill Evans and able to absorb blues, funk, gospel, and even modern classical influences, Hancock's piano and keyboard voices are enti...