Best symphonic and progressive singers

Steve Winwood, one of the greatest voices in the United Kingdom, could not be missing, encompassing soul, blues, jazz, gospel, and of course, what concerns us here, progressive rock. First with the Spencer Davies Group, whose version of "Georgia on My Mind" rivaled Ray Charles' original, and later "Gimme Some Loving" and "I'm a Man," which even Chicago reinterpreted, making it a classic at their shows.
Later, with his own group, Traffic, he fully embraced psychedelia, along with ethnic and progressive influences, without ever losing the brilliance of his vocal performance. From "Feelin' Alright," which Aretha Franklin herself would envy, to the epic "Crying to Be Heard," he couldn't miss the place he'd earned on his own merits as an instrumentalist, composer, and performer.