There are few phrases more frightening than “lounge music,” especially if it’s preceded by the term “fusion,” “crossover,” or, God forbid, “new age.” Images of a holistic acupuncturist’s waiting room are almost overwhelming. But there’s a fine line between pretentious and playful, and if a lounge act possesses the tact, skill, and sense of humor not to take itself too seriously, it can create a rich, textured musical atmosphere. On “The Cosmic Game,” their fourth studio album, Washington, D.C.’s Thievery Corporation treads this line cautiously, blending a subtle mix of world rhythms, space-age themes, and trendy celeb guest singers. Unfortunately, their interstellar balance tips to the weighty side a bit too often, which gets painfully repetitive. The album is little more than another soundtrack for burning incense or sipping lattes at Starbucks.

The album does have its saving graces: While “Cosmic Game” has the bravery to occasionally head in several directions at once, it also wisely maintains the same mood throughout. One song merges into the next, allowing the music’s atmosphere and complexity to build slowly over several songs. On the ethereal opening, “Marching the Hate Machines [Into the Sun],” the Corporation delicately layers quavering chimes over a slow-burning beat and some of the most opium-addled guitar licks since Lennon did “Sun King.” This morphs into the fast and funky “Warning Shots,” a reggae-industrial number that doesn’t skimp on the echo pedal. From there, a grab-bag of musical styles, from Indian bhangra, Brazilian roda to good ol’ American acid rock turn “Cosmic Game” into something of a global experience. The album pays homage to world music, while at the same time screaming Palm Beach at the top of its lungs.

But it really should lighten up once in a while. Maybe a stoned astrophysics major would get a thrill out of listening to songs like “Holographic Universe,” “Doors of Perception,” and “The Supreme Illusion.” But the Thievery Corporation more often sound like Bollywood or “Alias” than the ninth dimension. (Not that there’s anything wrong with fun, trashy techno — just don’t dress it in fancy clothes and call it a gem.) Thievery Corporation does the best they can with their frail Enigma impression, but unfortunately leave out the ultra-catchy hooks.

They also make a mistake of Santana-sized proportions with their litany of underground rebel celeb du jour guest singers. The ethereal, delicate “Hate Machines” is violently marred by guest singer Wayne Coyne of the Flaming Lips. His famously awkward singing and out-of-place lyrics vainly reach for some sort of grand political statement, but fall far short: “Well let’s start by making it clear/ Who is the enemy here/ We’ll show them/ That it’s not them/ Who is superior.” Why vocals even need to be here is a mystery, and why it comes from a usually-superb singer is a travesty. Needless to say, little on “Cosmic Game” comes close to the spiraling atmospheres of the Lips’ “Soft Bulletin.”

Other ill-conceived guest spots include Jane’s Addiction frontman Perry Farrell, who dishes on more ambiguously big ideas on the Indian-flavored (yes, another one) “Revolution Solution.” David Byrne, once of the Talking Heads, competently rides the jungle beat of “The Heart’s a Lonely Hunter.” If only the lyrics weren’t so befuddling: “Under the counter — well, that’s your nature/ Drip grind or roasted — buttered or toasted.”

All but three of the album’s 16 tracks feature guests, and most of them seem somehow ill-fitting. “The Cosmic Game” would be twice as good without lyrics, especially ones like Coyne’s and Byrne’s.

Unfortunately, the Thievery Corporation tries to maintain their lounge vibe, while simultaneously going mainstream with these pop mavens. Ultimately, their ambition far outstrips their talent — this album better suits a waiting room than headphones.