The 25th Hardly Strictly Bluegrass Festival kicks off Friday at the Golden Gate Park in San Francisco, with large crowds already arriving for opening day.

The free festival runs through Sunday.

This year’s event includes 15 performers who will weave Dolly Parton themes into their concerts.

Among the featured performers is Robert Plant, the legendary singer and original member of Led Zeppelin. Emmylou Harris is also among the artists in this year’s lineup.

The Dolly Parton tributes hold special meaning for longtime Hardly Strictly fans who wish they could have seen her performance at the festival 21 years ago.

NBC Bay Area’s Thom Jensen has the full report in the video above.