"We're either gonna have the biggest hit in the world, or the Beach Boys' career is over."

According to bandleader Brian Wilson's autobiography Wouldn't It Be Nice: My Own Story, that's how Beach Boys guitarist Bruce Johnston reacted after hearing the tapes for the group's next single, "Good Vibrations," in August of 1966. In hindsight, Johnston needn't have worried about the song — it would shoot to No. 1 after its release that October — but Wilson himself was clearly approaching the end of his tether.

Wilson's "Good Vibrations" journey started early in 1966, while he was working on what would become the band's classic Pet Sounds LP. Intrigued by a conversation he'd had with his mother, who suggested the idea that people give off vibrations of energy that animals are more in tune with than humans, he sketched the musical outline of a song he initially called "Good, Good, Good Vibrations." Stuck for verses after coming up with a chorus, he scheduled songwriting sessions with lyricist Tony Asher, and briefly entertained the idea of making the song part of the Pet Sounds track listing before deciding it wasn't ready yet.

The Beach Boys, meanwhile, were constantly on the road, fulfilling live obligations that Wilson had given up after retiring from the road in 1964. The arrangement gave him the freedom to indulge any and all musical flights of fancy without interference from his bandmates, but it also made it more difficult for the group to match Wilson's ever-more-exacting standards.

"Brian was absolutely at his peak back then. God, he was just like a freight train," Beach Boy Al Jardine later told Uncut. "We were hanging on for dear life. The Beach Boys were in and out of the studio day and night."

Wilson might not have had to maintain the Beach Boys' travel schedule, but he worked at a punishing pace while they were on the road. Feeling like he was at the summit of a creative peak — and on the verge of an even bigger breakthrough — he approached "Good Vibrations" as what he later called "the summation of my musical vision, a harmonic convergence of imagination and talent, production values and craft, songwriting and spirituality."

Even for a songwriter increasingly hailed as one of the brightest musical minds of his generation, this was a tall order, and Wilson turned to increasingly desperate measures — musical as well as chemical — in order to achieve his dream. During 17 sessions spread over three months, he enlisted an array of top-shelf musicians to bring "Good Vibrations" to life, melding a disparate-sounding list of instruments that included everything from fuzz bass, strings and woodwinds to the Theremin. As the sessions mounted, so did the studio bills, eventually reaching $75,000 — the equivalent of $550,000 after being adjusted for inflation, and an ungodly amount of money to spend on the creation of a single song.

"It was like he was scoring a movie. But 12 dates on 'Good Vibrations' – at three hours a date – is a long, long time to spend on one song," bassist Carol Kaye told Uncut. "It was very unusual. But the way he kept changing the music around was interesting. We knew he was trying to perfect a great hit. And we knew it was gonna be big."

While acting as studio ringleader, Wilson turned to drugs to help induce his preferred creative state, which ultimately exacerbated the fear and paranoia always lurking at the margins of his increasingly fragile psyche. Enthralled with the idea of putting together a sort of comedy-infused Americana song cycle, Wilson hooked up with lyricist Van Dyke Parks, who refused to tinker with the "Good Vibrations" lyrics but started working with him on other songs tabbed for the Beach Boys' next album.

As the pair collaborated, Wilson's connection with reality grew worryingly tenuous — as did his efforts to get a handle on "Good Vibrations." By the summer, he'd begun to worry that he and the Beach Boys wouldn't be able to do the song justice, and contemplated giving it to another band, but when associate David Anderle pitched it to Three Dog Night singer Danny Hutton — raving about it in the process — it gave Wilson the emotional boost he needed to take his recording the rest of the way.

Listen to the Beach Boys Perform 'Good Vibrations'

Even after he got past his own doubts, Wilson had to face the Beach Boys. He'd played a tape of the work in progress to his brother/bandmate Carl, who Brian remembered describing the song simply as "bizarre," and even after assembling what he was sure was the perfect mix, he encountered a mixture of confusion and indifference during that first playback session with the band.

"There was a lot of 'Oh you can't do this, that's too modern,' or 'That's going to be too long a record.' I said, 'No, it's not going to be too long a record, it's going to be just right,'" Wilson told Rolling Stone. "We just had resisting ideas. They didn't quite understand what this jumping from studio to studio was all about. And they couldn't conceive of the record as I did. I saw the record as a totality piece."

Nevertheless, Wilson managed to wrangle his bandmates on board for their vocal sessions, which included an ethereal lead vocal from Carl — who subbed in at the last minute for another Wilson brother, drummer Dennis, due to a case of laryngitis — and a key lyrical contribution from the most musically conservative Beach Boy, Mike Love.

"I came up with the part that goes: 'I’m pickin’ up good vibrations / She’s giving me excitations.' That’s my musical contribution," Love told Uncut. "I felt 'Good Vibrations' was the Beach Boys’ psychedelic anthem or flower power offering. So I wrote it from that perspective. The track itself was already so avant-garde, especially with the Theremin, that I wondered how our fans were going to relate to it. How’s this going to go over in the Midwest or Birmingham? It was such a departure from 'Surfin’ USA' or 'Help Me Rhonda.'"

Love's concerns regarding Wilson's artistic instincts would come to a point during sessions for the group's next LP, Smile, and he'd ultimately help pull the band back from what he viewed as a creative abyss after Wilson suffered a breakdown, leaving the record shelved for decades. But in the short term, the balance between Wilson's increasingly esoteric musical explorations and Love's commercial instincts continued to hold — and in the case of "Good Vibrations," it held beautifully.

Released on Oct. 10, 1966, "Good Vibrations" was an immediate smash, selling nearly a quarter of a million copies during its first four days in stores while beginning a rapid ascent to the top of the charts. Ultimately, the song became the Beach Boys' first million-selling single, and at the time, it looked like the perfect appetizer for the Smile album. Instead, it ended up being one of the band's final major singles before a period of declining sales and increasingly erratic behavior on Wilson's part.

Tantalizingly close to perfecting a pioneering style of songwriting and recording, Wilson shattered in the late '60s, and took years to work his way back from the darkness.

Looking back on "Good Vibrations" for Uncut, he struck a justifiably proud note regarding the song — and what it meant in the larger context of his art and the pop music of the time in general. "We all wanted to do something different, make some music that would last forever. Not just surf songs and car songs," he mused. "It was all about creating lasting music. And that led to 'Good Vibrations.' It was one giant step forward."