MANCHESTER, Tenn. -- The 2012 Bonnaroo Music and Arts Festival concluded Sunday (June 10) with a magical performance by the headliner -- the mighty jam band, Phish. But it wasn't just Trey Anastasio and the rest of the musicians who got the hefty crowd of "phans" and non- "phans" to sway and sing in unison. It was the one and only Kenny Rogers who joined Phish for a sweet version of "The Gambler."

That's right. Phish and Kenny Rogers.

And while that combination may seem like opposite ends of the musical spectrum, the fusion stitched together seamlessly. Sure, everything and anything goes at Bonnaroo -- from the party atmosphere to the clothing (or lack of). However, the true mystery and utterly astonishing element of the festival is how there are no boundaries to stay within when it comes to what kind of music will be played and heard. There are no guidelines, no coloring inside the lines and no limited access to the vastness of music that's created at Bonnaroo. This year was no exception.

Country fans would be proud of the presence bluegrass, folk and those sweet Southern jams had on the many concert stages at Bonnaroo this year. From the Alabama Shakes to the Civil Wars, that down-home spirit was represented Thursday (June 5) through Sunday.

Thursday kicked off just right with a little musical action from Rollin' in the Hay. Not only did the trio hype fans for a weekend of musical fun with "Opie Song," with its steadily-paced mandolin prompting the audience to stomp along, the early set prepared the crowd for days of immeasurable amounts of walking and uncontrolled dancing.

As the air began to cool by a smidgen and as the sky melted from an ombre-fire orange into a mellow navy, the Alabama Shakes took the stage. It was clear the chills received were reverbs of lead singer and guitarist Brittany Howard's downright soulful voice. It's a voice that's almost unbearably full of a life of blues that only she and greats like Etta James, Janis Joplin and Aretha Franklin possessed, that toppled over the souls of every person listening on that beautiful night.

A rosined bow and vigorously plucked strings of all sizes lit up the Sonic Stage on Friday morning as the Infamous Stringdusters performed "Don't Mean Nothin'." The classic sound of bluegrass in the morning ripened ears for more of that sweet sound. Fans got their fix shortly after with Sam Bush, the Grammy- winning multi-instrumentalist and a founder of newgrass music. He ignited the stage with the heat from his bow and the grit from his plucking.

As the set continued, the crowd around the stage grew, and Bush is a performer who knows how to keep any kind of crowd on the edge.

"It's a great circle of communication we get with the audience," said Bush in reference to performing for such a vast crowd.

The party didn't stop with Bush, though, as Trampled by Turtles and the Avett Brothers carefree, nonstop jamming bliss at the What Stage and the Other Tent. The sound of laughter, applause and opening cans of beer suffocated the air as the two bands tore through their respective sets, including the Avetts' "Kick Drum Heart."

While rapper Ludacris' bass beats were going strong in another performance space, Texas native Robert Ellis humbly took the Solar Stage with a performance that was soft and fitting after a long day of high-fiving neighbors while they chugged water and listened to their favorite songs. The longhaired, lanky singer-songwriter strapped a guitar to his chest and sang from his soul. With a voice that has a sultry, gently reassuring twang, he captures the essence of classic country similar to Willie Nelson. Ellis has a timeless quality that's refreshing in a world of complication

While it's easy to classify most acts into genre specific categories, labeling Ellis is a bit of a challenge.

"I just think of it as pop music," he said. "I write songs about people and relationships. They're simple enough songs. You can sing along to them. It's folk-pop. I tell people to go listen to it."

As the Saturday morning sun crept over the farm of Bonnaroo, the Devil Makes Three stirred up some energy as the red-hot firecrackers of bluegrass punk woke up the farm, substituting that need for a jolt of morning caffeine for banjo picking.

The Punch Brothers took the Which Stage later that afternoon. While they kept up with that skyrocketing, pulsating bluegrass energy, the musicians brought something a little different to the stage. Their harmonies were gently eased into creating intriguing, beautiful, cascading melodies. After their songs would dip into darker tones, lead singer-mandolinist Chris Thile would save the ship with his boyish voice that effortlessly soared around the musical cluster of bluegrass and classical music.

Even though the weekend was coming to an end, some of the brightest acts still had yet to perform. Multi-instrumentalist Sarah Jarosz and her band welcomed the crowd Sunday, and the 21-year-old Texan entranced the audience with a pure voice and a steady confidence.

She approached her songs with delicacy and thoroughness. Her voice was a web of naïve and untouched beauty that glided over every note and paired perfectly with the instruments accompanying it. Her brown curls danced with each chord she struck, and her ivory skin glistened as the sun began to filter though the heavy clouds, brewing above.

After Jarosz's set came to a close, fans camped out at the Other Tent as Kathleen Edwards, the Civil Wars and Rogers played later in the day.

Fans waved their hands and clapped along during Rogers' set as he sang his classics, including "Love or Something Like it." The laid-back country legend kept one hand in his pocket and the other gripped on the microphone as he sang to his adoring fans. During his set, he also introduced longtime friend Lionel Richie, who joined him for a duet of "Lady" before performing an impromptu version of his own 1983 hit, "All Night Long."

Between each song, a grin spread across Rogers' face as he heard the chants for more.

Earlier Sunday, Rogers talked about experiencing Bonnaroo and the impact music has on him and his fans.

"Music is the greatest memory-maker of all time," he said. "When you're young and you hear a song you love -- or you're older and remember where you were -- you remember who did it. And it always has a great place in your heart."

While Bonnaroo wasn't the typical concert setting for Rogers, he also talked about how much he values the listeners and the musical experience of any concert moment.

"I think that anytime you put a group of people together, you have something in common," he said. "You're going to get a great result.

View photos from Bonnaroo.