This is the legendary "The Dark Side of the Moon" in its highly collectible First UK Quadraphonic edition. This version features the original SQ (Stereo Quadraphonic) matrix system mix, which was specifically engineered by Alan Parsons to provide a 4-channel immersive experience. It is a distinct, dedicated mix that differs significantly from the standard stereo release, offering a unique soundstage and different placement of the album's iconic sound effects. As the very first quadraphonic pressing, it represents the pinnacle of 1970s audio experimentation and is a cornerstone for any serious Pink Floyd collection.