It took a long time: interpreting composed and improvised music as a unity. NEW YORK, NY - NOVEMBER 07: Aretha Franklin performs onstage at. JPG Garth Brooks and Trisha Yearwood perform together during the 2016 CMA. Bill Monroe The Father of Bluegrass had already defined a genre before. NEW YORK, NY - NOVEMBER 07: Aretha Franklin performs onstage at.