Dolly Parton

What separates Dolly Parton from virtually every other major country star of her era — and most eras — is that she writes the overwhelming majority of her own material as both lyricist and composer. Where Nashville peers like Kenny Rogers built careers almost entirely on outside songs and Luke Bryan relies on a professional songwriting pipeline, Parton authored the words and music of her biggest hits herself: 'Jolene,' 'I Will Always Love You,' 'Coat of Many Colors,' '9 to 5,' 'Light of a Clear Blue Morning' — all entirely hers. 'I Will Always Love You' is a particularly striking case: Whitney Houston's blockbuster cover made it one of the best-selling singles of all time, but every royalty dollar flows back to Dolly as sole songwriter. She is the rare superstar for whom authorship and performance are one and the same — a songwriter's songwriter operating at the highest level of commercial success.