Through the doors of the Durant Recreation Center in Alexandria, past a glass case that once held athletic awards, stands a room that long ago housed a basketball court. Little of the court remains, covered now with risers anchored where the court's lines were once painted.

Tall mirrors face the risers on one wall and hundreds of photographs of members (of what could be called a team) line the side walls, where basketball nets once hung.

Every Tuesday night, as they have for the last 40 years, the men in the photographs file through the building's doors, shaking hands, patting backs, chatting loudly, catching up on the week's events.

Then they get down to business -- barbershop singing.

These men make up a group known as the Alexandria Harmonizers, a barbershop chorus that today has 205 members. Born in Alexandria more than 40 years ago with 16 members, the group has met every Tuesday night at the recreation center for as long as most of them can remember.

"Long ago, we shared the room with a bunch of kids who would come in here to shoot baskets," said Terry Jordan, a member of the group since 1965, "but we just kept singing and I guess that ran them out."

The group has expanded and refined its repertoire over the years to include hundreds of ballads from the barbershop to Broadway. It now performs in places such as Constitution Hall, the Washington Convention Center, the Kennedy Center and the White House.

Members also appear at community benefits, and folks even stop by to watch them rehearse. About 70 members perform in quartets and compete in local and national contests.

But it wasn't always like this.

Henry Brown, one of the original members, remembers when the chorus started in 1948.

"Our first performance in the rec center was fairly miserable," said the longtime Alexandria resident. "We had people in the group that really couldn't sing well and maybe never would. These days, if you put your mind and soul in it, we have coaches that help you with the technical part."

The group is one of approximately 820 chapters in the Society for the Preservation and Encouragement of Barbershop Quartet Singing in America, an organization that was formed in 1938.

In 1986 and 1989, the chorus was the International Barbershop Chorus champion. It is also a six-time recipient of the society's Achievement Award for best overall chapter.

To keep its appeal and hang on to its blue ribbons, the group has added voice coaches and an arranger who handles choreography. Members now sport white tuxedos with glittering blue vests and bow ties.

"When we started, you could just stand there and sing. Now you have to move more," Brown said.

Rehearsals last for three hours each week. One night two weeks ago, musical director Scott Werner clapped and barked out commands about everything from pitch and range to dance steps.

Lined up on the risers, members of the chorus watched themselves in the mirror while singing, smiling constantly (an important part of "stage presence"). A small group of wives sat on metal folding chairs, one of them sewing a competition patch on her husband's jacket.

Barbershop singing dates back to the 1800s and is considered one of the four original American musical art forms, along with country, gospel and jazz, according to Wilbur Sparks, another longtime member and the society's historian.

"People used to get together and sing at home and in public up until about the 1930s," he said. "But with the proliferation of the radio and the demise of vaudeville, people stopped participating and started watching."

According to Sparks, two men from Tulsa, Owen Cash and Rupert Hall, recognized the decline in barbershop singing in their town and started their own local group in 1938. "Within a few years, a trend had spread nationwide and it evolved into the society," he said.

A barbershop quartet, which is what the chorus is based upon, is made up of four men or four women, but rarely a mixed group. A list of old songs (almost all written before the middle of this century) are sung a cappella by a lead singer, a tenor, a baritone and a bass. The lead almost always sings the melody.

A chorus follows the same basic rules but has more freedom of style because of its larger number of singers.

"Stylized harmony is a prominent aspect of barbershop singing," said Sparks. "This permits a lot of liberty in note values, pitch and range."

"A singer from the 1930s would be amazed at how we sing now," said Jordan. "It has really progressed. When barbershop singing began, the singers would chop every word off at the end. Now, the sound is like molasses; the words and notes flow into each other and there isn't that break."

The group, once composed of a small group of Alexandria residents, now has members from diverse backgrounds and different locales. One member, a lawyer, lives in Richmond and makes the drive every Tuesday evening to rehearsal. Most members are middle-aged or elderly government employees and private businessmen. Singing brings them together, and from there friendships are founded.

"It's like another family," said Royall Geis, who has been a member since 1983 and whose wife, Geri, is the group's artistic director and choreographer.

"It started as a hobby and turned into a way of life," Brown added. "When you get together with a group of people every week, you make a lot of friends."

Geoff Berman, one of the younger members of the group, said he joined because he "couldn't believe how friendly everyone was."

"I was in a bar one night with some friends and this group of guys was sitting in a corner singing. They invited me over . . . and we sang 'Sweet Adeline.' The next week, I began going to rehearsals," he said.

Friendships are apparently what keeps groups such as these alive, and their popularity continues to spread. There are several choruses in the metropolitan area and many have formed around the world, reaching from Australia and South Africa to Canada. Even Russia has its own group, which recently performed with the Harmonizers at Carnegie Hall.

Sparks said because barbershop quartets originated in the United States, the music is American, which means foreign groups sing in English.

To Harmonizer members, the benefits of song obviously outweigh the drawbacks, of which there is at least one.

"After all these years, I'm hoarse," said a laughing Henry Brown, who hasn't sung with the group since last year. But he agrees it was worth it.