They are missionaries of music, questers of standing ovations. In a city where memo- writing has been raised to an art, they are do- it-yourselfers. Their reward is not of this world: Working 70 hours a week, and juggling jobs and free-lance assignments, they achieve only middle-class income. TINA CHANCEY SCOTT REISS

They are pioneers of medieval, Renaissance and baroque music; their small apartment is crammed with reproductions of musical instruments superseded by the standardization that began in the 18th century.

Tina Chancey, 33, is in charge of the strings, which range from the vielle, a portly ancestor o the violin, to the lozenge-shaped, nasal-voiced kamenc, still popular from Bulgaria to Iran. Scott Reiss, 31, presides over recorders varying from 8 to 40 inches in length, with tones from reedy to throaty. Chancey and Reiss, friends for 10 years, were married a year ago.

Chancey directs the Washington Academy of Early Music, which she founded in 1981. "We hold classes and workshops," she says. "We have a core of 40 students."

Reiss heads Hesperus, which he calls "the first baroque ensemble in Washington made up of Washington musicians." During its first season, Hesperus toured historic houses in Virginia; this year its schedule calls for four concerts at the Corcoran.

They work for each other. Chancey plays the viola da gamba--which looks like a cello but is closely related to the guitar--in his Hesperus; Reiss teaches at her academy. They both perform with the Folger Consort.

"Early music is a fringe in the music business," Chancey says.

"Early music is soft, personal, intimate," Reiss says. "We can't amplify, and the maximum comfortable audience is 600 people.

"Our re-creation is sometimes authentic. We try to be reasonably accurate, but if there is a choice, we always go for a good performance." TONY AMES

Headquartered in a Georgetown townhouse featuring posters, an Art Nou veau love seat and a rural dry sink, Tony Ames is a musician, impresario, propagandist. His projects are complex and numerous, and he is their best salesman. But in the middle of his pitch, he rolls his eyes, laughs and wonders if his projects are good only for losing money.

Ames, 40, is the principal percussionist at the National Symphony and runs Potomac Productions--"a full-scale musical service, offering music for every occasion, from private parties to the Washington Opera Terrace Theater." He is also cofounder and director of the Millennium Ensemble, "a unique group comprised of five chamber music organizations" including the 20th Century Consort, which is "a modern music group in residence at the Hirshhorn."

Ames believes that it would be "reactionary of us to play only melodious music" and searches for pieces of contemporary music that are "sensual." He says that Washington audiences are reacting positively. "The audience for contemporary music is across the board," he says, "including people who like rock and middle-aged people who like theater and painting, and people who just like things that are different." REILLY LEWIS

The group Reilly Lewis, 38, founded began playing the works of Johann Sebastian Bach in 1977, and, if all goes well, it will have performed all of Bach's vocal and instrumental music by the end of this century.

The Washington Bach Consort is made up of 40 singers and 20 instrumentalists, none of whom is paid. They perform the cantatas in the Church of the Epiphany downtown, and the oratorios and passions in other churches throughout the city. In 1981 the Consort toured both Germanies; Lewis says it is the first American ensemble ever to receive an invitation to perform in Thomaskirche, Bach's church in Leipzig.

"Bach is everything," Lewis says. "You can be transported without knowing the technical details. And once you learn about the technical details, Bach is clear, precise, perfect. His music is a perfect work of art. Nothing needs to be added.

"He didn't trust performers. He wrote down every little detail. So Bach is frustrating for those who like to add their flair, to express their individuality. But I think the key to Bach lies in a purging process: focusing on the total work while stripping away those glorious techniques and sculpted details. My approach is to flow back and forth between instrumentalists and singers. They are equal parts of a whole. The key is to be integrated, absorbed.

"Life without Bach would be barren." ED MATTOS

Concert pianist since age 5 and harpsichordist for 10 years, Ed Mattos, 60, calls himself "first of all and best of all a musician." He describes his appointment as director of The Barns as the equivalent of the electric train set he had always wanted.

Transplanted from Upstate New York where it was built in 1725, the barn is "an acoustical paradise," Mattos says. The programs he has developed cover "a gamut, from jazz to chamber music," with an emphasis on "a highly personal, intimate contact" between performers and audience. That contact has "started to wear thin since the 19th century," he says, "but, oh boy, we need it."

The Barns, part of Wolf Trap, has 350 seats. "Small is great if you can afford it," Mattos says. "Remember, before Beethoven, music was played in one's house."

Surrounded by mementos of his 19 years in the Foreign Service, Mattos lives in a comfortable suburban house. He talks about art's civilizing influence--how art "reminds us that we can be better, more graceful. TV is passive; the difference between it and live art is enormous. Live performance increases our respect for the liveness of word and deed. It takes human beings to do that; it can't be done technologically."