The marathon musical test in endurance that is the Bonnaroo Music & Arts Festival opened up in earnest as the Friday portion of the schedule boasted more than 16 hours of eclectic performances. Although Sir Paul McCartney would go on to capture the hearts and imaginations of everyone in attendance with his magical headline performance, there were plenty of less legendary acts working to take full advantage of the famous Bonnaroo atmoshpere. Here's what happened. Hard to believe there are still two whole days to go.

Wake Up Call: Whether you're weary-eyed after a long drive or suffering a hangover from Thursday night, making it into Centeroo on Friday with anything resembling a high energy level is a tough task. Over on the Main Stage, dreamy folk outfit Local Natives managed to provide the aural adrenaline shot everyone needed, as the lush, breezy harmonies of new single 'Breakers' and 'Sun Eyes' wafted over the large field in front of them.

Breakout Performance: Although Mumford & Sons won't be making their scheduled appearance at Bonnaroo this year, memories of their star-making 2011 Which Stage throwdown came to mind as the Icelandic folksters Of Monsters & Men had crowds packed in beyond the large bobbleheads at the back. There wasn't one person within ear shot that could resist singing along to smash hits 'Mountain Song' and 'Little Talks' as the band's 'Roo debut served to further cement their upper-tier status.

Criminal Conflict: The Wu Tang Clan rose and reformed on the Which Stage, bringing with them a classic-filled set and a wild house-party feel. Sadly, this overshadowed an otherworldly, soulful showcase from Bonnaroo best friend Jim James. The My Morning Jacket frontman took those who made it out to This Tent on an exploratory creative journey backed by a fantastic light show and a thunderous fuzz-rock sound. It was a rare treat to see such a dynamic artist in his most natural environment.

Best Quote: Passion Pit took the Main Stage for their first Bonnaroo set since 2009 and it was clear that frontman Michael Angelakos was having himself a very good time. In his effervescent tone, the singer repeated with genuine awe after each song, "Holy s---, Bonnaroo!"

Picture Perfect: There are many indelible images that pop up through the grounds of Bonnaroo, but there's always that one moment or performance where the Tennessee weather and landscape blend with what's going on to make for a postcard-worthy memory. That particular joy came this year during a performance by Grizzly Bear, who brought their recent 'Shields' material to life in gorgeous psychedelic fashion. Large clouds moved and shifted almost in tune with the rolling guitars of 'Sleeping Ute' and the jazzy rhythms of 'Gun-Shy.' By the time Grizzly Bear ignited with 'Two Weeks,' the Friday evening spirit of Bonnaroo had reached full swing.