Day one of the Hard Rock Calling music festival in London kicked off with unseasonably beautiful weather, i.e. no rain. The location for the fest in Hyde Park made for a beautiful backdrop for the show’s two stages.

In the mid-afternoon, Jason Mraz brought his sunny, laid-back jams to the main stage. Sporting an open white shirt, gray slacks and a black straw fedora, his California style seemed in tune with the day’s weather. Going along with that vibe, Mraz and his backing band strummed through a fun, free-spirited cover of Oasis’ “Wonderwall,” as well as the classic Seals and Crofts cut “Summer Breeze” and Bob Marley’s “Three Little Birds” (a.k.a. “Everything’s Gonna Be Alright”).

John Mayer picked up where Mraz left off, as the crowd began to pack in for the night’s headliner, Eric Clapton. Clapton’s influence on Mayer was obvious — the guitar virtuoso played through his catalog of blues hits, and also had some fun with the audience.

“I like this crowd because you’re into blues music,” Mayer said as he pointed to a man in the front row. “My job is to make the guy in the Eric Clapton shirt unfold his arms.” By the end of the set, he had.

Mayer’s closing number, “Gravity,” got a huge response from the crowd once people recognized the opening chords. By this time, the park had become so dense with fans that even the paved walkways separating the grassy areas had become filled in.

Before leaving the stage, Mayer shared with the Hard Rock Calling crowd how fortunate he felt to take the stage before his legendary predecessors.

“If I get to be on the same stage as Eric Clapton and Sheryl Crow in the same day, I know I’ve done something right,” Mayer said.

After that came Sheryl Crow, decked out in all white with an acoustic guitar. She opened with the politically charged “God Bless This Mess,” and once that was over she ripped off her guitar strap and broke into “Shine Over Babylon.” The songstress continued through her set with her many hits, keeping the crowd on its feet for the night’s biggest act.

Promptly at 8:15 p.m. Clapton took the stage, right on time, in front of fully packed, shoulder-to-shoulder crowd. He began his set with his bluesier material as the sun slowly started to set. His voice has aged some, but it seems perfectly fit for the blues. Seeing him effortlessly bend the chords on his guitar was like watching a sculptor massage through a mound of clay.

Halfway through his set he began to amp up the energy with the crowd favorites “Wonderful Tonight” and “Layla.” He rounded out the night with “Cocaine,” and there’s nothing like listening to forty-something thousand people sing the lyrics to that song.

The highlight of the night came when Clapton brought out a surprise for his encore — a few surprises, actually: John Mayer, Sheryl Crow and Robert Randolph. The foursome played Clapton’s classic “Crossroads” as the crowd went ecstatic. After an almost-two-hour set it was the icing on the cake to what was a perfect summer day in the park.

Check out a recap of day two, as well as more photos at MattgomeryBurns’ profile page on yourhere.mtv.com.