"When you mix classic country with this new-age country music, it's great," said Zach Greenwood, 25, of Walnut Creek. "I grew up on George Strait, Garth Brooks and Alan Jackson, but it's good to see country mixing with other styles."
Messina Johnson, 23, decked out for the day in a cowboy hat and boots, tank top and cut-off shorts, came from Sacramento to see Lynch, Dylan Scott and the rest of the lineup, which included nearly a dozen acts over two days.
"I grew up on a ranch," Johnson said. "I've always listened to this kind of music. I've never listened to anything else."
Sunshine beamed down brightly on the massive outdoor stage, flanked by big video screens, as some of the 11,000 fans meandered past stands selling beer and kettle corn, or took a turn on the mechanical bull ride.
As cool breezes blew in, the music got hotter, with the pounding bass and drums and screaming guitars of the bearded Texas quintet called The Eli Young Band. But true to country tradition, the band paused for a ballad titled "Prayer for the Road," dedicated to the families touring musicians leave behind.
Saturday's roster moved toward mainstream with the closing act of the festival, Darius Rucker, who achieved pop fame as the lead singer for Hootie and the Blowfish from 1986 to 2008, before launching his current career as a solo country singer.
The crowd roared as Rucker hit the stage, opening with "Radio" and building up to his current hit, "Wagon Wheel."
The festival's first day drew a crowd of 6,000 Friday to hear Hunter Hayes, Joe Nichols and others.
The event's executive producer, Alan Jacoby, who partnered with the fairgrounds and country radio station Froggy 92.9 FM, said he hopes to bring Country Summer back to Santa Rosa next year, but it's too early to say for sure.
Jacoby said he was inspired to put together this year's event after presenting the hit country duo Florida-Georgia Line at the Sonoma County Fair last year.