"Tango is like a vast underground river," says Joan Singer who's not a singer at all, but a violinist in the local tango group QuinTango. "And it's a river that has been running strong and constant this entire century all around the world regardless of what's hot in the media."

Well, go ahead, bite the hand that's about to praise you! Because this little corner of the media has decided that QuinTango is one of Washington's finest instrumental ensembles and should be added to everyone's I-gotta-check-those-guys-out-sometime list.

In 1995 Singer was a member of the Capital Chamber Ensemble, along with pianist Bruce Steeg and bassist Libby Blatt. The group was on a European tour that year, and one night in Holland after a show, one of the promoters of the concert invited the ensemble to check out his tango group. "We had our instruments, and we jammed with his group on some [Astor] Piazzolla and it was magical," Singer says. (Piazzolla being Argentina's most influential composer, responsible for creating more complex, orchestral forms of tango throughout much of this century).

"I remember the piece we played in the Hague that night, Piazzolla's `Soledad,' and I didn't know much about Piazzolla but the music was so compelling. Some music just grabs you and tells you what to do, and that's how I felt. I had to play this music." Singer was soon recruiting members to join her, Steeg and Blatt in a tango troupe. Violinist Rachel Schenker and cellist Irma Field Cripe signed on, and within a year, the quintet (thus the name) was performing in front of audiences.

The members immersed themselves in the tango repertoire, listening to hundreds of records, old and new, to decide what pieces to perform. "There's not a lot of sheet music to this material, so I've commissioned a number of arrangements for pieces that we've wanted to play," Singer says. (On QuinTango's excellent debut CD, released last November, there are several commissioned arrangements and some from their Dutch friend, Frits Vonderveen, the one who sparked all this.)

"The pianist in a tango orchestra pretty much improvises everything," says Singer, "but the rest of the parts are written. But you can go with your heart and not your head with this music. You can add ornaments, little flourishes, play a part an octave higher, hold a note three times longer than it is on the written page and no one will say a thing. One thing about our group is that we trust each other when we play together. We allow each other our flights of fancy, because at heart everyone is a very, very passionate performer."

Ah, passion. What this highly structured music and its concomitant dance is all about, no? "Oh, completely. I was totally seduced by this music. It is about passion. The music and the dance are very basic. About a man and a woman. That's about as basic as it gets. And it's straight from the heart."

The music, despite Piazzolla's innovations, remains highly structured, since its evolution in the dance halls of Argentina late in the 19th century. A hybrid of northern European chamber music, dance hall polkas, Mediterranean and African rhythms, the frankly erotic tango created a scandal in Europe before taking it by storm in the years preceeding World War I.

It still carries with it a vague sense of turn-of-the-century decadence and extravagance, and QuinTango's passionate (there's no other word) readings of the music's nearly sacred texts send the listener's brain to far-off -- and perhaps imaginary -- places. "It's like a scent or a perfume," agrees Singer, "one that reminds you of something you can't quite put your finger on. There's some tug of nostalgia, but, really, nostalgia for what?"

See QuinTango Monday night at the Institute of Musical Traditions' concert at the Paint Branch Unitarian Church in Adelphi (301/263-0030). You can find out more about the group and future performances by checking its Web site, www.quintango.com, or by calling Singer at 703/548-9148. Washington also has an active tango dance scene, one I'll be covering in a future column, but you can find out more about this by calling the Capital Tangueros at 202/546-2228, Ext. 36.

To hear a free Soundbite from Quintango, call Post-Haste at 202/334-9000 and press 8113. (Prince William residents, call 690-4110.)

CELEBRATING CASSIDY

Three years ago this month, the Washington music scene lost one of its very brightest lights when singer Eva Cassidy succumbed to cancer. Just 33 at the time, Cassidy had just hit her stride with a superb CD that blended blues, jazz, folk and pop, and everyone around here knew that national success was a real possibility. Her illness kept most of the world from learning what an incredible vocal artist Cassidy was, and to keep her name alive, Cassidy's parents, Hugh and Barbara Cassidy have announced the formation of the Eva Cassidy Foundation, a non-profit group dedicated to assist music education programs in area elementary schools.

The creation of the foundation was spearheaded by Cassidy's longtime friend Laura Caliguiri, who says the idea had been germinating for a long time. "For me it was something I always wanted to do to celebrate Eva," says Caliguiri, "to somehow thank her for all of the happiness she gave me and everyone who heard her, to give something back."

The foundation doesn't have much to announce just yet in the way of activities, beyond a rough outline of what its directors would like it to be. "In the beginning, we're going to work with one school a year, focusing on its needs, then we'll see about expanding," Caliguiri says. She said that it was Cassidy's father Hugh's background in education and music that led to the decision to help school music programs. "I'm a special ed teacher in P.G. County schools," says Hugh Cassidy, "but I was certainly aware of the cuts in funding for music teaching, and I thought helping those musical needs would be a different and worthy thing to do, and something Eva would have been proud to be part of."

Hugh Cassidy talked with the head of the music department for P.G. County schools and found a nearly endless list of needs: "Everything from fiddle strings to reeds for the horns to money for rental instruments, money for programs to bring in working musicians, money for music summer camps, money to pay for outside lessons when needed. There are so many areas where we can help."

Cassidy used to play bass ("I played rock and roll back in the '50s at places like Benny's Rebel Room downtown"), but nine years ago took up the cello, now a solid passion of his. "Music should play a part in everyone's life, and so many folks miss out on that from lack of lessons or from the lack of interest shown by someone else. We hope to help that situation." He says that royalties from his daughter's record sales will help seed the foundation, "then with Laura's help, we'll get going on some fund raising."

"I think starting early next year we'll be doing a lot of fundraisers," Caliguiri says. "I think ideally we'd like them to be musical fundraisers where local bands play. So many friends of hers in the music scene have come forward saying they'll help, it's been very encouraging. We've got lots of avenues for people interested in helping."

For more information, call Caliguiri at 202-234-0043.