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I don't know about 40 years from now, but I can tell you that two of the most influential people of 40 years ago barely made a dent on the radio.
Alex Chilton had only one real hit, which was "The Letter" by his band the Box Tops, but later made more famous by Joe Cocker.
But his later band Big Star, while pretty much completely unknown to the mainstream, is a huge influence on all kinds of bands today.