I don't think that you can underestimate the influence of the Ink Spots on this genre of music. Between 1940 and 1949 they had 18 top ten hits on the US Pop charts. They were the first black performers to appear on television, and in 1948 they were the first black performers to appear on the Ed Sullivan Show. and made multiple appearances there and on the Milton Berle and Steve Allen shows. Their biggest hit, and one of the biggest hits ever, If I Didn't Care, was written by a Jewish guy Jack Lawrence, and many of their other hits were written by white Tin Pan Alley professional songwriters. The original vocal group broke up in 1954, but hundreds of unauthorized versions with no original members have sprung up since. I saw a version of the Ink Spots in the 1980s and they were great, but they had no original members.