The guitar is a versatile, expressive instrument, but it isn't everything.

It's easy to forget that if the mainstay of your musical diet is rock 'n roll, which these days is as guitar-driven as ever. Hard rock dominates most "alternative music" sections, and it more or less requires a prominent guitar. Styles vary, but when it comes down to it, one guitar-based band speaks the same language as any other.

For music in a different tongue, give a listen to "Yes," the fantastic new album from Morphine. As on the band's previous releases, "Good" and "Cure For Pain," the sound of Dana Colley's baritone sax and Mark Sandman's 2string slide bass comes as a welcome surpriseÑa musical shot in the arm, if you will.

There's really no way to understand what Morphine sounds like except to hear it. The sax-bass combination suggests blues or jazz, but the band's narrative complexity and rhythm don't fit either title. Morphine calls itself "low rock," which is as appropriate a label as any. The slide bass sways, throbs, murmurs near the bottom of hearing; the baritone sax moans as if burdened by emotional weight. And the lyricsÑhalf Raymond Chandler, half Jack KerouacÑare as laid-back as a patient under anesthetic.

Sandman, also the band's songwriter and vocalist, sounded on "Cure For Pain" as though he'd just woken up and needed a cup of coffee. Apparently he got it, because "Yes" is considerably more up-tempo. The flames on the sleeve are an indication of the fiery rhythm within; Colley manipulates his horn into seizures of satanic rapture, while drummer Billy Conway steps up the hi-hat action and sends his sticks into syncopated overdrive. The accelerated pace leaves less room for the mordant self-pity that played such a central role on the first two albums.

From the opening track "Honey White," a sardonic tale about a junk-food junkie's deal with the devil, the album establishes a mood of playfulness and experimentation. Sandman's deadpan wit flavors songs like the finger-snapping "Sharks" ("Don't worry about the day-glo orange life preserver/ Swim for the shore just as fast as you're able.")

"Free Love" is a half-angry, half-amused response to the naivetŽ of the love-starved. "The next time someone offers you free love," Sandman sings, "you better run for the cynical arms of a stranger/ Because love is expensive."

The song that most embodies the album's feel, "Super Sex," is a string of apparently random words ("Automatic taxi stop electric cigarette love baby/ Hotel rock'n'roll the discoteque, electric super sex") sung over a blare of crosstown traffic sax and card-shuffle drums. It was written for Morphine's foreign audiences, who love the montage of "American" imagery.

There's not a track on "Yes" that isn't excellent, but my current favorites are "Whisper" and "The Jury."

"Whisper" concerns the slippery laws of flirtation. "Don't worry, I'm not looking at you/ Gorgeous and dressed in blue," Sandman sings with a seductive play at disinterest; "Though we haven't even spoken, still I sense there's a rapport." Punctuated by a dark piano chord, the song has a stylishly dangerous, film noir feel.

In "The Jury," an experimental spoken-word piece, the lyrics shift back and forth between ominous courtroom jargon and lush descriptions of food and drink. Sandman's voice alternately purrs and drones, sighs and accuses.

Again, "Yes" is remarkably free of weak spots; these "favorites" are only the tracks that happen to be echoing in my head at the moment. Every song is memorable in its own way, freshened with an irresistible bass line, a delicious sax hook, or a particularly clever turn of phrase. There's something compelling about the dour romanticism of Morphine's approach, an almost cinematic sense of entertainment to their explorations of lust, luck and longing.

Though "Yes" is a generally upbeat album, it closes with a melancholy ballad about an abandoned lover, "Gone For Good." A touching list of all the things he'll never do again, it is also the only moment on the album when a guitar is heardÑa reminder of the language spoken in the majority of pop songs. Morphine's six-string fluency can be matched or surpassed by many musicians, but for the incomparably sweet rush that "low rock" provides, no other band comes close.