Ambient-rave music was pioneered by Orb helmsman Alex Paterson, who in the late '80s DJ'd a "chill-out" room at a London dance club where overheated techno ravers could unwind to the sounds of placid galactic blips and shimmering electronic oceans. The tones and textures he devised were more of an evolution than a revolution – merging the atmospheric minimalism of Terry Riley, Harold Budd and Brian Eno with the heady psychedelia of Pink Floyd and the buoyant pulse of Jamaican dub – yet they effectively heralded a new generation of electronic sound.

After the Orb released two groundbreaking albums – The Orb's Adventures Beyond the Ultraworld and u.f.orb – innovation surrendered to trend. Dozens of ambient groups surfaced, including Aphex Twin, the Future Sound of London and Orbital, but none could capture the Orb's mind-altering vision and sophistication. Like the best space rock (Pink Floyd, Hawkwind, Tangerine Dream), the Orb's music provided sheer escapism, taking listeners on a trip deep inside the imagination. Today many of the band's contemporaries are still dabbling in flotation-tank music, but the Orb have moved beyond hallucinogenic sedation into more provocative realms of mood enhancement.

Orbus Terrarum, the Orb's new record, is a sonic bridge between the drifting dubscapes of u.f.orb and the chaotic but somewhat directionless noise experiments of last year's EP Pomme Fritz. As such, it's the band's first disc to demonstrate real continuity. While much of the Orb's past output wafted like gaseous vapors that never strayed far from their places of origin, the new album meanders through a cryptic obstacle course toward a distant psychic finish line.

Along with the traditional cache of lunar waves and pulsar beats comes an endless supply of sound effects, from chirping birds and crickets to bubbling geysers and whizzing spaceships. Dub rhythms are few and far between, often vanishing to accommodate flurries of synthetic noise. At times the seemingly random splash of effects makes it sound as if the band's equipment were malfunctioning. At other moments computerized water droplets and delicately gliding synths are all that separate the music from true ambience. Even at almost 80 minutes in length (between seven and 17 minutes a song), Orbus Terrarum never sounds long-winded.

Much of the album is orchestral in design, with songs that ebb and flow like symphonic movements. And like works by Igor Stravinsky or John Cage, the tracks contain melodic motifs that provide cohesion even when little else does. What makes this music arresting, however, is the way the Orb provide tension by juxtaposing a wide variety of beats, noises and melodies. On "Oxbow Lakes" a spare, eloquent piano line reminiscent of Eno's Music for Airports is bombarded by what sounds like a tumultuous meteor shower, and on "Montagne d'Or (Der Gute Berg)" an echoing pedal steel guitar struggles to be heard over a crashing industrial beat.

Orbus Terrarum is a dense, convoluted record, for sure, but it's not difficult or pretentious. Credit this to the Orb's oddball sense of humor – a quality that further separates the band from the horde of computer geeks that holds every keyboard bleep sacred. The Orb have demonstrated their sharp and uniquely British wit on the music variety show Top of the Pops by sitting in front of the cameras playing chess while they were supposed to be performing, as well as by gracing the cover of their 1993 live album with a wide-eyed stuffed toy sheep flying over the Battersea power station (an obvious reference to Pink Floyd's Animals cover). Levity is unquestionably a key ingredient of the Orb's artistry, and Orbus Terrarum is their most amusing offering to date.

During the unsettling clatter of "White River Junction," a soothing voice from a self-help tape ironically comments, "You are a happy person full of imaginative thoughts.... Accept the friendship people offer you, for you truly deserve it" – a wry allusion to the therapeutic New Age reputation of ambient techno. Other samples are more bizarre. The relatively upbeat "Occidental" features a computerized voice that repeatedly intones, "Right here, right now," over the beat, a tongue-in-cheek poke at the Jesus Jones hit.

But the most whimsical banter comes during the epic psychedelia of "Slug Dub," a contorted Peter and the Wolf for the Tarantino generation peppered with snippets from one of Paterson's favorite children's stories. In it, a distraught family's lettuce crop is destroyed by slugs until the youngest son befriends a bird that eats the garden pests.

With Orbus Terrarum, Paterson has created an auditory experience that stretches the limits of ambient techno. Instead of aiming to chill, the Orb are now determined to thrill. (RS 706)

JON WIEDERHORN