@Rarebear Actually, bluegrass gospel is considered a subgenre of gospel, rooted (as is bluegrass proper) in American mountain music; I would actually call it a hybrid. Gospel Music is defined by The American Heritage Dictionary as A kind of Christian music based on American folk music, typically marked by strong rhythms and elaborated refrains and incorporating elements of spirituals, blues, and jazz.
Gospel music, IMHO, is true folk music. It has roots stretching back centuries, and spanning continents; it brings influence in from many other genres. Whether you are talking about Bluegrass Gospel like Ricky Skaggs; or Southern Gospel a la The Statler Brothers; or what’s called “traditional” Gospel like Might Clouds of Joy I don’t think it’s any more traditional than any of the other types or subgenres! —They all fit within the definition above.