MAYBE YOU THINK the price of a song has shot through the roof these days, especially when it comes to quality classical music. Well, think again.

Washington may have its share of $60 orchestra seats, but it's also one of the best places in the world to enjoy inexpensive, highly professional classical performances.

Not only that, but when you start to scratch the surface, a lot of what's available isn't just cheap. It's free.

To help you take advantage of the opportunities, we've put together a sampling of places, groups and suburban symphony orchestras that offer free concert series. And just for good measure, we've tossed in some other suburban orchestras that offer high- caliber performances at relatively low prices -- ranging from $5 to $12.50.

A classical experience isn't that hard to come by if you know where to look -- and listen.

SITES FOR SORE EARS

BETHUNE MUSEUM ARCHIVES -- 1318 Vermont Avenue NW. Offered on selected Sunday afternoons at 3, the museum's free series (although a $1 donation is requested) features the work of young black musicians. Season highlights include: Nov. 17, soprano Annette Pierson Poulard; Jan. 19, "Amore Trio," with violinist Celia Moulyn, cellist Charlotte Moulyn and pianist Russell Woollen; March 9, mezzo-soprano Valerie Eichelberger. 332-1233.

LIBRARY OF CONGRESS -- Coolidge Auditorium, Thomas Jefferson Building, 10 First Street SE. Last year's tickets were a whopping 25 cents, but this year's are free if you make a reservation in advance. Besides its regular Friday night series, the library presents occasional Saturday afternoon programs and some special events on other evenings. The performers are usually first-class. Season highlights include several premieres: Oct. 30, 8 p.m., soprano Phyllis Bryn-Julson, pianist Donald Sutherland and the Atlantic String Quartet in "Ode to Henry Purcell" by Vivian Fine; Nov. 18, 8 p.m., baritone David Hamilton and pianist Stuart Raleigh perform "Lyrical Interval," a song cycle by Hugo Weisgall. For reservations, call 287-5502 between 11 and 1 on the Saturday before a concert.

NATIONAL ACADEMY OF SCIENCES -- 2100 C Street NW. Arts in the Academy's free concerts, given on Friday evenings at 8 in the auditorium of the National Academy of Sciences, usually combine modern music with established classics. Five of the eight concerts in this series are performed by the academy's ensemble-in-residence, National Musical Arts.

Season highlights include: Nov. 22, National Musical Arts performs its first commissioned work, the premiere of "Time . . . And Again," by Barbara Kolb; May 16, guest soprano Carmen Pelton performs "To Wake the Dead," a work by 1985 Pulitzer Prize-winner Stephen Albert. 334- 2436.

NATIONAL GALLERY -- East Garden Court, West Building, Constitution Avenue between Seventh and Fourth streets NW. Under the direction of George Manos, weekly concerts, Sundays at 7 p.m., sometimes feature the gallery's own orchestra, more often young soloists or chamber ensembles. A notable feature of this series is its frequent use of relatively unfamiliar repertoire, particularly during its American Music Festival each spring. Season highlights include: Nov. 3, an all-British program with the National Gallery Orchestra to complement the gallery's "Treasure Houses of Britain" exhibit; Dec. 1, Trio Brasileiro. 842- 6076.

PHILLIPS COLLECTION -- Music Room, 21st and Q streets NW. Free concerts at 5 p.m. every Sunday, with strong emphasis on young, relatively unknown artists. Some of the most famous musicians of our time (Glenn Gould, for example) played here before they were famous. Season highlights include: Feb. 9, a concert with pianist Theodore Lettvin to mark the 30th anniversary of the first concert he played at Phillips; April 13, the Manhattan Marimba Quartet. 387-2151.

WESTERN PRESBYTERIAN CHURCH -- 1906 H Street NW. The free Thursday lunch-hour concerts here (six in the fall and eight in the Spring), sponsored by "Music At Noon," have attracted a loyal clientele among people who work in the neighborhood of George Washington University and the World Bank. Season highlights include: Oct. 31, "Dreams Into Sound," a concert of French music with duo pianists Bonnie Kellert and Barbara Wing. 842-0068.

GROUP FARE

AMERICAN CHAMBER ORCHESTRA -- Anderson House, 2118 Massachusetts Avenue NW. Drawing its membership from the National Symphony, this orchestra, under the direction of William Yarborough, gives free concerts, usually at Anderson House. However, its next performance is the opening concert for Arts in the Academy on Nov. 9, 3 p.m. at the National Academy of Sciences, 2101 Constitution Avenue NW. The organ soloist for the program is Douglas Major. Other highlights, at Anderson House, include an all- orchestral program, March 15, 3 p.m. 244-0756.

FRIDAY MORNING MUSIC CLUB -- New York Avenue Presbyterian Church, 1313 New York Avenue NW. Just beginning its 100th anniversary celebration (the celebration spans the 1985-1987 seasons), the club offers a well-varied free program called "Music at Noon," featuring Washington area musicians, at noon each Friday.

FMMC also offers a variety of other free concerts throughout the year at various locations, including another series entitled "Centennial Celebration Concerts." Highlights of the "Music at Noon" series include: Nov. 1, the FMMC Orchestra and conductor Robert Gerle perform with violinist Adela Pena; Nov. 8, soprano Susan Read, violinist Melissa Graybeal and pianist Victoria Bontempo. 628-2264.

PAUL HILL CHORALE -- Paid admission is required for most of the group's programs, but it has recently been offering a free program, with themes drawn from the Gettysburg Address. It will offer that program at the following times and locations in the metropolitan area: Oct. 27, 6 p.m., St. Luke's Episcopal Church, 1514 15th Street NW; Nov. 3, 6 p.m., Plymouth Congregational Church, North Capitol and Riggs Road (a $7 donation will be requested at this concert); Nov. 9, 3:30 p.m., Sligo Seventh Day Adventist Church, 7710 Carroll Avenue, Takoma Park; Nov. 10, 7:30 p.m., Cathedral of St. Thomas More, Cathedral Lane and Route 50, Arlington. 364-4321.

WASHINGTON BACH CONSORT -- This group, which usually performs on Sunday afternoons in downtown churches, is well-advanced in a long- range project to present the complete works of Johann Sebastian Bach.

Season highlights include: Nov. 3, 3 p.m., National Presbyterian Church, Nebraska Avenue and Van Ness Street NW, Mass in A minor, Cantatas 79 and 89, D minor Toccata and Fugue, and the Washington premiere of the transcription for solo violin of the D minor Toccata and Fugue, with organist Peter Marshall and violinist Jody Gatwood; May 11, 8 p.m., Church of the Ascension and St. Agnes, Massachusetts Avenue at 12th Street NW, performing, as part of the Washington Bach Festival, the Mass in F major, Ascension Cantata No. 128, and others. 337-1202.

SUBURBAN ORCHESTRAS

Everyone knows about the National Symphony and its internationally famous conductor, Mstislav Rostropovich, but this is only part of the orchestral scene in Washington. Suburban orchestras abound, and one is probably closer to your own front door than you realize.

Of these, the Fairfax Symphony is the most critically acclaimed. Also of note: the Montgomery Chamber Orchestra began last year at a remarkably high level of quality and has doubled its season this year from four concerts to eight.

Quality varies from one group to another, but the best are very good, and all are enjoyable.

We'll start with the free ones:

ARLINGTON SYMPHONY -- Performs its free concerts on selected Sundays at 3 at the Kenmore Auditorium, 200 S. Carlin Springs Road in Arlington. A series of guest conductors are featured for its next five concerts. That schedule: Nov. 7, David Pollitt; Dec. 8, John Welsh; Feb. 9, Thomas Ludwig; March 9, Joel Lazar; April 6, Andrew Litton. 558-2165. ARLINGTON UNITARIAN ORCHESTRA -- Performs its free concerts at the Unitarian Church of Arlington, 4444 Arlington Blvd. Highlights include: Nov. 10, 7:30 p.m., guest pianist Russell Woollen performs Hindemith's "Four Temperaments." The orchestra and church choir will also perform Beethoven's "Sea-calm and Prosperous Voyage," "Elegy," and an aria from "Fidelio." 892-2565.

MOUNT VERNON CHAMBER ORCHESTRA -- Usually performs its five or six free concerts a season on Sundays at 7:30 at St. Aidan's Episcopal Church, 8531 Riverside Road, Alexandria. Season highlights include: Oct. 27, a concert with violist David Basch and oboist Dorothy Darlington; Nov. 17, a performance of Bach's "Magnificat" and portions of "St. Matthew's Passion." 360-4953.

NORTHERN VIRGINIA SYMPHONY -- Performs its free concerts at Reston Community Center, 2310 Colts Neck Road in Reston. Conducted by Lawrence Wheeler, the season opens Nov. 23 at 8 p.m. with Dvorak's Symphony No. 8. 450- 2530 or 450-2537.

And now for the moderately priced suburban orchestras:

ALEXANDRIA SYMPHONY -- No permanent location. Tickets are $7, $5 for students and seniors, free for children under 12. Highlights include: Dec. 7, 8:30 p.m., Alfred Street Baptist Choir performs Bruckner's "Psalm 150," oboist Marion Arthur performs Dittersdorf's Oboe Concerto. Also, Mahler's Symphony No. 1, Menotti's "Introduction" march, and the Shepherd's Dance from "Ahmal and the Night Visitors." T.C. Williams High School Auditorium, 3330 King Street, Alexandria. 548-0045.

FAIRFAX SYMPHONY -- Under the direction of William Hudson, it performs alternately at Fairfax High School, 3500 Old Lee Highway, and the Kennedy Center Concert Hall. Tickets are $12.50, $8 for students and seniors. Season highlights include: Nov. 17, 3 p.m., pianist Leonard Pennario is the guest for an all-Rachmaninoff program at the Concert Hall; Feb. 15, 8 p.m., soprano Irene Gubrud sings Strauss' "Four Last Songs." Also on the program, which will be held at Fairfax High, are works by Beethoven, Ravel and Korngold. 821- 8118.

McLEAN ORCHESTRA -- It usually performs seven concerts a season at the McLean Community Center, 1236 Ingleside Drive, McLean. Tickets are $7, $4 for students and seniors. oncert highlights include: Nov. 23, 8 p.m., a chamber ensemble of the orchestra's woodwinds and brass sections in a performance that includes Copland's "Fanfare for the Common Man" and Handel's "Royal Fireworks Music." 281-8702

MONTGOMERY CHAMBER ORCHESTRA -- Under the direction of Piotr Gajewski, it performs monthly on Saturdays at 8:30 at the National Bureau of Standards on Clopper Road in Gaithersburg. Tickets are $12, $10 for students and seniors. Season highlights include: Nov. 9, Mozart's Serenade for Winds, Copland's "Appalachian Spring" and Brahms' Serenade in A major; Dec. 7, bassoon soloist Carolyn Fedderly is the guest and the program includes Corelli's "Christmas Concerto," Mozart's Bassoon Concerto, Hindemith's Four Pieces for String Orchestra and Grieg's "Holberg Suite." 926-1606.

PRINCE GEORGE'S PHILHARMONIC -- Under the direction of Ray Fowler, it performs once a month at the Queen Ann Fine Arts Theater at Prince George's Community College. Tickets are $10 reserved, $8 unreserved and $6 for students and seniors. Season highlights include: Nov. 24, 3 p.m., a program of Chabrier's "Espana," Mozart's Piano Concerto No. 11 and Brahms' First Symphony. Soloists will be the winners of the Senior Concert Competition of the Prince George's Music Teachers Association; Feb. 8, guest artist, violinist Jody Gatwood. Program includes Bach's Brandenburg Concerto No. 3, Bruch's Violin Concerto No. 1, and works by Ravel and Faure. 699-2540.

VIRGINIA CHAMBER ORCHESTRA -- Performs alternately in Old Town, 115 S. Washington Street in Alexandria, and at the Wolf Trap Barns. Tickets are $10. Season highlights include: Oct. 27 at 8 (Wolf Trap) and Oct 28 at 8 (Old Town), Nadja Salerno-Sonnenberg, guest artist, performs Vivaldi's "The Four Seasons." The program also includes Mozart's "Eine kleine Nachtmusik," and Handel's Concerto Grosso Op. 6, No. 7. 356-8201.