Constance Eller, violinist extraordinaire and founder of the group, calls the trio's music "Gypsy Chamber Jazz," which suggests the intimacy of the acoustic trio format, while giving a nod to the eternally swinging music made in the 1930's by gypsy guitarist Django Reinhardt, in company with Stephane Grappelli, the great French violinist. But the "gypsy jazz" tag conveys only a part of the Vipers charm and reach. For one thing, the trio's repertoire is vast and ultra-hip, nonchalantly cutting across categories and expectations. A swing-era gem by Artie Shaw is followed by McCartney's "Blackbird," or Harrison's "While My Guitar Gently Weeps" -- the latter done as a jazz-waltz, Viper-style. The arrangement flatters the melody, as does their rocking take on "La Bamba."

Many songs are largely improvised on the spot -- a musical high-wire act that demands jazz instincts and great technical ability. Fortunately, the Vipers are well up to the job. Eller is classically trained and, in a former life, played at Tanglewood and Lincoln Center. She can break your heart with her tone and virtuosity -- if she wants to. She's played with the Spokane symphony, and more recently, the Gonzaga University symphony. She can play Bach and Vivaldi all day, but would rather have a go at, for example, Fats Waller's "Mean to Me," throwing in a sultry, Berlin Cabaret-style vocal, along with the collective instrumental wizardly. Jazz Violinist are a rare breed. Besides the great Grapelli, jazz buffs will remember America's Stuff Smith and Joe Venuti. Cornetist Ray Nance also played violin for Duke Ellington Orchestra on occasion, and Eddie South, an overlooked genius, made some scintillating jazz violin records in the 30's and 40's. Find them if you can.

The trio format can be unforgiving. Each member is exposed and vulnerable, and there must be no weak links. No worries -- the trumpet part of the equation is handled brilliantly by Michael Lenke, like Ms. Eller a local product, though widely-traveled and experienced. Lenke, who also plays the mellow fluegelhorn, is unduly modest about his abilities. He will be the last one to tell you that as a younger man he toured as a member of the Maynard Ferguson Big Band, one of three in a trumpet section behind the great Ferguson, a trumpeter famous for his range and high-register power. Happily, fortunately, though he has "chops" in spades, Lenke has chosen a different path than Maynard. His goal is not to blow down walls of Jerico -- he'd rather seduce you his gorgeous tone and melodic embellishments, never excessive, his horn always in service to the song. Like Eller, he is not afraid to play "prettily," and he is a master of playing the horn softly, like Chet baker on a good night. Unlike Chet, or Miles Davis, Lenke likes to play "dirty" as well, shifting to a lascivious growl, muted or otherwise, when the song calls for it. Lenke also takes an occasional vocal, singing in a rich baritone voice, but most of all, he is the perfect horn player for Red Velvet Viper. Just be aware he can blow the roof off the joint anytime he decides the time is right.

Rick Luna plays piano, of the portable type, and wisely eschews the electronic effects afforded by "electric" keyboards. He favors the natural acoustic piano sound, a philosophy perfectly i tune with the Vipers organic, no-gimmicks sensibilities. He is a completely unselfish player, and, like Lenke, is too modest about his abilities. Without a drummer or bass player, it is Luna who must provide the rhythmic foundation for the band, a challenge he meets with aplomb to spare, invoking the percussive qualities of the piano. But then listen to him take a solo turn, the right-hand doing inventive, wonderful things with the melody, while the robust left propels the music forward, calling up echoes of the great stride piano players of past years. There is never the deadly-dull "cocktail lounge" feeling to anything he plays. Luna is also a polished singer and the group's primary vocalist, singing everything from Cole porter to Richie Valens with warmth and a casual sincerity. He comes from a family where musical ability runs deep, and it shows. Like Lenke, he is perfect for the unique Viper sound, and is nothing less than an equal third of the whole.

And something really must be said about the "Fourth viper," Brendan McMurphy. He is a hugely-inventive, golden-toned trumpet player who sits in when Lenke's preexisting commitments to other elite musical groups render him unavailable. Still in his twenties, McMurphy is affectionately called the "Baby Viper," but his musical and jazz instincts are mature and true, and he, too, is a perfect fit.

At the height of their powers -- when, for example, Eller's violin is singing the melody to Leonard Bernstein's "Maria," adjectives such as "sublime" and "exquisite" come to mind. In an age of hyperbole, it's wise to be cautious before throwing out all these adjectives. But even after due reflection, neither term seems like an over-reach.