Five hundred and ninety-one consecutive weeks on the Billboard charts. Seven hundred and twenty-four weeks on the Billboard Top 200. Over twenty-five million copies sold. Normally one would be right when saying that commercial success in the fields of music doesn't always reflect quality, but this is THE exception. The Dark Side of the Moon was arguably Pink Floyd's culminating moment; a display of sheer songwriting perfection that was equal parts brilliant music and insightful lyrics, and that has been critically hailed for decades. It is a journey through the mind and how modern life's pressures can drive one insane; a concept that is enhanced through the spacey musical atmospheres that constitute the majority of the album and that flow into each other effortlessly. So effortlessly, in fact, that the entire album seems as if though it were but one impossibly absorbing and never-ending song. Moreover, an album that can be played in perfect synchronization with The Wizard of Oz deserves bonus points. If you ever have to take a single album with you on a trip to the moon, make sure it's this one. And make sure you visit the dark side.

"Speak To Me" - A persistent heartbeat. Frantic voices. Typewriters. Steps. Manic laughter. Helicopters. Screaming. Welcome to the madness…

"Breathe In the Air" - With David Gilmour's soothing guitar and Roger Waters' relaxed bass giving the music a platform on which to slide gracefully, "Breathe In the Air" sends the listener floating slowly away while the band keeps on playing. And while one smiles cozily, a gentle group of arrangements enhances the warmth of this musical hearth before the track's dual vocals go up in tranquil waves of air. Then it's a sudden explosion from keyboardist Rick Wright that wakes the listener momentarily before allowing for a second peaceful reverie, in which one is finally subdued by sleep and beauty while knowing, with tranquil hopelessness, that things are starting to take their toll.

"On the Run" - Paranoia, neurosis, stress, it's all weighing in on the mind, and Nick Mason's steady high-hat beat is the frontal drill, boring a maddening hole into the central nerve. This is not enough, however, as a stubbornly persistent and irritating central sequence is toiling away at sanity, and the pressure is constantly heaving, despite the occasional truce. Samples, voices, voices, voices, voices, voices. You've been welcome here before, now experience the madness before the debris is left behind.

"Time" - After the gala of special effects that its predecessor is, "Time" could only start in kind with an enormous cacophony of chiming clocks, alarms, and such before settling in on a curiously relaxing tick, which in turn is surrounded by a sparse collection of aural embellishments that turn it into a magnificent prelude. The atmospheric beats of Mason, meanwhile, contribute to building the grand hall of sound before Gilmour brings a Southern-drenched wail to his guitar and is intensely accompanied by the rest of the band.

Then it's off to a sad moment of introspection that is backed by a wonderful female choir and contrasts sharply against Gilmour's previous harsh and desperate vocals. But what gleams with undisturbed quality is his subsequent solo; proof of his gut-wrenching capabilities and precious timing of guitar bends, which tug away at the heart with inescapable emotion. By then, the return to his harsh vocal desperation and a following reprise of the main theme behind "Breathe In the Air" only serve to enhance what is already an emotional discharge of the most beautiful kind.

"The Great Gig In the Sky" - And what a gig it is. Using Wright's gentle-tempered piano as soft basis and spacey guitar slides from Gilmour as preparation, Pink Floyd explodes into an intensely atmospheric instrumental that serves as background for singer Clare Torry's soul-drenched screams and Wright's dominating keyboards, after which his initial piano segment comes back in soothing splendor. That, however, doesn't prevent Torry from offering the remainder of her soul to the listener, which she does in befitting fits of feeling that adorn Wright's splendid flow.

"Money" - Who said that a 7/4 bass line can't be infectiously catchy? With Waters providing the most contagious groove this side of the planet, as well as wonderfully sarcastic lyrics that are cleverly accompanied by intermissions on behalf of Gilmour and Wright, "Money" walks forward with a contemptuous demeanor and an incredibly zesty feel. But that's without counting guest saxophonist Dick Parry's wonderfully raunchy solo and Gilmour's very own, the latter taking place above a jazzy chromatically descending bass line that is just dying to be heard. Tasty.

"Us and Them" - Another trademark Pink Floyd song that floats gently through atmospheric piano and keyboard chords and splashes into heart-rending segments that are backed up by a female choir and led forward by desperately touching vocals. But the atmospheric quality of "Us and Them" owes just as much to the warm saxophone touches that are sprinkled across its duration and the echoing vocals of David Gilmour, which give the track an undoubtedly introspective nature. Wright's performance, meanwhile, is at its most emotive here, with a mid-section solo so warm that it sends the listener back again into childlike peacefulness and wonder while the rest of the song drives into majestic crescendos and, for every time it does so, quiets down with a subdued gentility.

"Any Colour You Like" - Starting out with keyboard-drenched atmospheres of lush beauty and a bass that remains the cornerstone of the track's absorbing progression, "Any Colour You Like" is an instrumental that once again allows Gilmour to shine through in his manipulation of feeling with a solo that is at once gentle and commanding. It is here that Pink Floyd is at its thickest, placing layer upon layer of sound until critical mass is reached, at which point Gilmour initiates the gentle descent.

"Brain Damage" - The lunatic is on the grass. And in Gilmour's carefully chosen notes, picked with a laid-back tranquillity that belies the accumulating tension behind his clean arpeggios, which in turn explodes upon intense segments reminiscent of the grandeur of "Us and Them." But the effect here is markedly different, as there is no return to lucidity or serenity, but rather an intrusion in the fields of strange lunacy, as perceived in the maniacal laughter that surfaces midway through the song and complements the track's ironically calm lyrics. Wright then takes it upon himself to drive the listener further down as he plays a childishly twisted theme, leaving one with absolutely no possibility of turning back.

"Eclipse" - The end of all ends. A resounding grand finale of epic proportions, "Eclipse" features Wright's keyboards in atmospheric full force and the brilliantly employed female choir of the album wailing away in the background, which, as usual, works splendidly. Additionally, Mason executes his percussive responsibilities with hearty vigor, driving the track forward in a waltzing manner that gives ample ground for the song's evocative vocals. This is where all things are drawn to an end. Welcome to the dark side of the moon.

-by Marcelo Silveyra