Let's look at some Doo-Wop.* Arlene Smith, founding member of the Chantels, the second successful black "girl group," was 15 when she wrote and recorded "Maybe," which is still considered to be genre definitive. Smith also wrote "He's Gone" and "Every Night (I Pray)." Rolling Stone Magazine called her, "the best female vocalist in the history of Rock 'n Roll." I'm not sure I can place her over Janis Joplin or Aretha, but her voice certainly has the same emotional impact. Somehow, she doesn't even rate a Wikipedia page.
(*Though the first recorded Doo-Wop songs date back to the end of the thirties, notably The Ink Spots' "My Prayer," the term was not applied to define the genre until '61, three years before the end of that era. Still, the term can be heard earlier in the 1955 hit, When You Dance by The Turbans, and the 1956 song In the Still of the Night by The Five Satins. The name comes from the "nonsense syllables" commonly sung in this type of music, possibly from from the onomatopoetic term for vocalizations that mimicked the "doomph" plucking of a double bass, as sung in Count Every Star by The Ravens (1950)