In addition to Stevie Wonder's impeccable musicianship, this album features contributions from Nathan Watts (bass), Raymond Pounds (drums), Greg Phillinganes (keyboards), Ben Bridges and Mike Sembello (guitar) and a guest appearance by jazz pianist Herbie Hancock. To produce the album, Wonder and the group worked in the studio relentlessly for two years, occasionally logging sessions of 48 hours straight. These efforts paid off with a number of excellent jazz, blues and gospel-influenced songs, including "I Wish" and "Pastime Paradise." The album also includes the Duke Ellington tribute "Sir Duke," in which Wonder acknowledges his debt to the African-American musical tradition. Selected for the 2005 registry.