[To read an introduction to The Great Voices Project, click here.] [To read previous portions, of the list, click the following links: #50-#46 … #45-#41 … #40-#36 … #35-#31 … #30-#26 … #25-#21.] ———————————- #20: Sam Cooke He may not know much about history, but Sam Cooke absolutely knew how to sing. Considered one of the greatest soul voices of them all, Cooke was able to sing many types of music. Cooke was one of the greatest hit-makers of all time, charting 29 songs in the top 40 in just seven years. Tragically, he was shot to death at the age of just 33. While he started as a gospel…