From Rolling Stone:
Gladys Horton, a founding member of the pioneering Motown girl group The Marvelettes who sang lead on their 1961 classic "Please Mr. Postman," died January 26th in Sherman Oaks, California from complications related a stroke. She was 66.
Horton formed The Marvelettes (then known as the Casinyets) at Michigan’s Inskter High School with members of her Glee Club when she was just 15. A 1961 talent show caught the attention of one of their teachers, who arranged an audition at Motown with Berry Gordy and Smokey Robinson. The two-year old label had no experience with girl groups, but they signed the group â€” largely based on the powerful vocals of Horton and her group-mate Wanda Young.
In the summer of 1961 Motown released their debut single "Dear Mr. Postman," which featured Marvin Gaye on drums. It eventually shot to Number One and the Marvelettes were put on the road. "We went through hell on those tours," Marvelette Wanda Young recalled in J. Randy Taraborrelli’s 1986 book Motown. "It was so bad â€” the traveling, the food, the accommodations â€” that Juanita [Coward] went right into a nervous breakdown. We had to put her under medical care and she left the group in 1963." Despite the difficulties, the group’s success helped transform Motown into a major record label and paved the way for The Ronettes, The Supremes and all girl groups that followed.