Sturgill Simpson joins Forecastle. | Courtesy of Sturgill Simpson

The more the merrier seems to be the mantra for the 15th annual Forecastle Festival, as organizers have just added more than a dozen acts to the already impressive lineup. Those joining the party include Kentucky native Sturgill Simpson and Austin indie rockers Spoon, along with Phantogram, Capital Cities, Tycho, Real Estate, K. Flay, What So Not, Whitney, Classixx, Joseph, Chicano Batman, Jaye Jayle, Jeffrey James, Oyster Kids, and*repeat repeat.

“The 15-year anniversary of Forecastle reflects the eclectic, innovative and stimulating spirit that has propelled us forward since our humble beginnings in Louisville’s Olmsted Parks,” said Forecastle founder J.K. McKnight in a press release. “It’s a party with a purpose: a unique cross section of culture and activism, coupled with the most interesting, impactful artists you’ll find anywhere in the country.”

Spoon! | Courtesy of Spoon

Simpson appeared on “Saturday Night Live” just last month, and his latest release, A Sailor’s Guide to Earth, is up for Album of the Year at the Grammys. Ambient music performer Tycho also is up for a Grammy this year for Best Dance/Electronic Album.

Spoon returns to Forecastle to promote their latest, Hot Thoughts, which comes out March 17.

Forecastle will take place at Waterfront Park July 14-16. Headliners include LCD Soundsystem, Weezer, Odesza, Cage the Elephant and P.J. Harvey. Tickets are currently on sale, although the daily lineups have not yet been announced.

Here are a few clips to get you psyched for the show; first up are two from Sturgill Simpson’s much-lauded appearance on “Saturday Night Live”:

And here’s an oldie but goodie from Spoon: