Trey Anastasio probably wouldn't be confused with a folk act, even if the former frontman for the jam band Phish stepped on stage solo with an acoustic guitar. The same goes for the Black Crowes, whose bluesy guitar-driven rock would easily drown out the average acoustic troubadour.

But both acts are on the bill for the upcoming Newport Folk Festival, which this year features a genre-bending mix of marquee performers that draw big crowds but don't fit snugly under the traditional folk umbrella. The lineup is a way for the venerable festival to stay relevant amid a glut of summertime concerts while deepening the audience base for a tradition-rich event best known for the year Bob Dylan swapped his acoustic guitar for an electric one.