Back for his fourth Rock the Garden concert, Charlie Schafer held up his cup of Summit beer as he noted the big difference between this year and previous years.

"I'll probably be drinking a little bit less today just to pace myself for tomorrow," said Shafer, 32, of Maple Grove.

A membership-driving fundraiser for Walker Art Center and Minnesota Public Radio that doubles as one of the Twin Cities' biggest outdoor music festivals, Rock the Garden doubled its lineup this year by adding a second day for the first time. Conversely, tickets failed to sell out for the first time in seven or eight years of the event, which dates back to 1998.

Neither the concertgoers nor organizers were complaining, though — especially after a week of heavy rain gave way to crystal-blue skies, which dried the Walker's Open Field grassy knoll in time for the more than 10,000 attendees to spread out on the slope adjacent to the Minneapolis Sculpture Garden.

"We got a beautiful day and kicked off with two great local music acts, so we're thrilled," said David Safar, music director at MPR's 89.3 the Current.

Shafer, an MPR member, said the two-day changeover "opened the show up to more people who weren't able to get tickets before, and it opened it up to having more Minnesota music on the lineup."

For the first time, the Current’s Rock the Garden was extended to a two-day event, after years of shows quickly selling out.

Between gigs in England — where she will play the Glastonbury Festival next week — Minneapolis' buzzing rapper Lizzo kicked off the most hip-hop-heavy lineup in RTG history, with De La Soul the headliner Saturday and Dessa due up Sunday. A transplant from Houston, Lizzo did not let Saturday's blazing sun temper what she called "one of my 'some day' dream gigs."

"It was better than the temperature in Duluth last night," Lizzo said backstage after her set, noting that temperatures dipped below freezing for her gig before the Grandma's Marathon.

Fresh from playing solo gigs across Europe, Minneapolis singer/songwriter Jeremy Messersmith went big with his homecoming gig, expanding his band to a 10-piece ensemble.

"I have half the Twin Cities up here," Messersmith wryly noted as he introduced the Laurel Strings in his band, a quartet that added elegant tones to such songs as "A Girl, a Boy & a Graveyard" and his new album's opener, "It's Only Dancing."

Bethany Cosentino of the Californian wave-rock band Best Coast told the crowd, "You guys sure know how to do the first day of summer."

In the long water-fountain line atop the Walker's hill, 30-year-old Blaine music lover Chad Torkelson said he's more excited to see Sunday's RTG performers — especially headliner Spoon — but was happy he decided to come both days.

"We don't have enough music festivals or outdoor venues in the Twin Cities," Torkelson said, "so you have to take advantage of this one."

See a full Rock the Garden wrap-up in Monday's Variety section or online at startribune.com/music.

Chris Riemenschneider • 612-673-4658