A few weeks ago, VH-1 aired a documentary on the making of some Fleetwood Mac release -- either Rumours or Tusk, it hardly matters which. Lindsey Buckingham sat behind a console, fiddling with knobs and dials until he managed to separate out each piece of one particular song: He isolated the vocal tracks, the myriad guitar lines, the bits and pieces of percussion, the elusive and indecipherable effects piled one on top of the other. Like a mad surgeon, Buckingham sliced open his creation to reveal the tiniest pieces inside -- not just the heart and muscle, but every blood cell and excretion. And in the process, he absolutely ruined the mystery that is at the heart of the best rock and roll. Buckingham let us see how he put together his music, when all he ever had to do was let us hear it. Or just feel it.

And so it is with the long-delayed The Pet Sounds Sessions, a four-disc box set that spills Pet Sounds' guts all over the floor -- every note repeated again and again, every vocal track and every run-through included, every Brian Wilson instruction and every mistake revealed. It's a box for fetishists, those who would seek to understand how Wilson constructed his masterpiece from beginning to end. It pulls back the curtain and reveals the midget standing on the ladder, stripping away the intrigue until Pet Sounds' 13 perfect songs become dozens and dozens of half-finished, start-and-stop-and-start templates. It's a how-to kit that comes with a 120-page instructional manual -- not to mention two versions of the completed product itself, one in stereo and the other in mono. Never before have we been given such a chance to see a genius at work; never again will we want one.

Pet Sounds undoubtedly ranks among the most important rock and roll releases of the past 30 years. It's the record that inspired the Beatles to make Sgt. Pepper's, the record that merged pop and psychedelia, the record that ushered teen music into adulthood. It's essential listening, especially for those who would dismiss the Beach Boys after witnessing the golden-oldies act now relegated to playing state fairs and summer festivals. Sometimes, you can listen to Pet Sounds and it feels as though it's the place where pop music begins and where it ends, where joy turns to sorrow turns to near suicide. It's a document of heartbreak and fear, filled with one man's songs about how he doesn't fit in, how he longs for escape to a place he'll never find, how he longs for the sort of love he will never know. It's as much about surrender as it is about celebration, and it's still surprising to discover just how many of Brian Wilson's twisted demons we call our own. It never hurts to listen just one more time to "God Only Knows" or "Don't Talk (Put Your Head on My Shoulder)" or "Wouldn't It Be Nice." They're perfect love songs -- teardrops on a smile.

Pet Sounds was also about how Wilson couldn't find the answers in drugs or religion but only in his music, this luxurious and textured sound that comes on like a whisper and leaves like a train. If anything, The Pet Sounds Sessions places you inside Wilson's anguished head for a moment, letting you (sort of) understand why he went this way instead of that way. You can hear him giving instructions to the myriad musicians piled into the studio, telling them to stop doing that and start doing this instead. Of course, there are reasons they leave this kind of stuff off the finished product: It's interesting only until it detracts from the results. Do you really want to see Georges Seurat put all those little dots to canvas, or would you rather just gaze at the finished painting and marvel at how much effort it took?

Given such, the "stack-o-vocals" collected on disc three are perhaps the most rewarding moments. It's exhilarating to hear the unadorned, swelling harmonies of the Beach Boys, most of whom weren't too thrilled to sing Wilson's anguished lyrics after years of having so much fun, fun, fun on those odes to surfing, cars and California girls. These cuts prove Pet Sounds wasn't only about the intricate arrangements: It was about the words, the angst, Brian Wilson's romance with pot and misery. The a cappella selections only underscore the lyrics. Without the arrangements getting in the way, "Sloop John B," for instance, finally becomes less a folk standard performed Beach Boys style and more about "the worst trip I've ever been on." In retrospect, it's comical that Capitol released "Sloop John B" as Pet Sounds' first single: If anything, it contains the release's most blatant drug reference, and it sums up Wilson's intentions better than any song on the record. Pet Sounds was one long bad trip, a comedown after so many highs.

Ultimately, The Pet Sounds Sessions isn't as rewarding as listening to the original release on its own. There's little pleasure to be gained from drowning in the details. Wilson understood that the best music came when you put the music and words together, when they formed that inexplicable third element -- when the words made you think, the music made you feel and the song made you whole. Whole -- that's the way Pet Sounds should be heard, not in disconnected pieces. Whole -- that's when it's a perfect masterpiece. Otherwise, it's just a perfect mess.