During the past 21/2 years, Cecelia Osowski has spent a few hours each weekend on musical dates with her father. On Sunday evenings, they make the 15-minute drive from their home in Lincoln to Leesburg Presbyterian Church, where they rehearse with the Loudoun Chorale.

The 15-year-old alto joined the adult choral group in the fall of 2001, after her mother took her younger sister to a soccer match one weekend. Rather than stay home alone, Cecelia tagged along with her father to a chorale rehearsal.

"They were doing the 'Messiah' with the Loudoun Symphony," Osowski recalled. "I sat next to this lady who sang very loud, so I could hear exactly what the notes were. And I practically had it memorized."

She liked the experience so much that she continued attending the rehearsals and soon became a member.

"I asked the director [whether Cecelia could join] and he said, 'No problem at all,' and she's had a blast," said her father, Tim Osowski, 39, a bass who has sung in the chorale for eight years.

As a home-schooled student, Cecelia Osowski has had to seek out musical experiences that other students get in the classroom or as extracurricular activities. When she was younger, she sang in her church's children's choir. In recent years, she has focused more on playing cello in a youth orchestra at Shenandoah University and has taken on small ensemble roles in Loudoun Valley High School's drama productions.

Patrick McConnell, 17, stumbled upon the Loudoun Chorale in much the same way Osowski did. His mother, Debby, joined the group as a soprano at the beginning of last season and, midway through, asked if he would be interested in singing with them, too. "Of course," the recent Broad Run High School graduate recalled saying.

"I wasn't quite sure what to expect when I got in," said McConnell, a baritone who sings in his school choir. "You don't often see music as difficult as you see in choirs like that when you're in high school. After the first rehearsal, I was pretty much glowing. I loved it. I still do. Singing in a group that large is amazing."

In the past, a few high school students have joined the 60-member chorale for special concerts. But the chorale has never added such young singers to its regular roster until Osowski and McConnell came along, according to Jean Demyttenaere, 77, of Bluemont, a soprano and one of the chorale's founding members.

The Loudoun Chorale was formed in 1992 after several Purcellville churches that had come together annually to sing Handel's "Messiah" realized that some of their singers wanted to sing together throughout the year.

They began rehearsing at St. Andrew's Presbyterian Church in Purcellville. But they wanted to reach out to singers in eastern Loudoun, so they moved their rehearsals first to Trinity Lutheran Church in Leesburg and then to their current location at Leesburg Presbyterian.

Along the way, the chorale attracted members from Fairfax County and as far away as Front Royal.

"I've sung in other groups, and this is the warmest, most friendly group I've ever been with," Demyttenaere said. "And we made a real effort at that in the very beginning, because we felt that everyone should feel welcome and come and enjoy the companionship. . . . To be in an adult group that has an enthusiasm and warmth, they learn so much from that. I mean, we're truly setting an example for these kids."

The chorale performs three to four concerts a year. Although its members do not have to pass auditions, the level of repertoire has remained challenging throughout the chorale's 12-year history under four directors. It has tackled large classical choral works, such as Brahms's "German Requiem," Mozart's "Requiem" and Schubert's "Mass in G." This past season, the chorale focused on works by American composers.

"There have been times when people have come and found the music a little harder than they had anticipated, and they drop out," Demyttenaere said. "But we didn't want to turn anyone away who had a real interest in good choral music."

Members pay $50 annual dues and purchase their own music to help defray operating costs. Funding from county sponsors and advertisers and arts council grants provide for the accompanist, Beverly Clark of White Post, and director, Tianxu Zhou of Leesburg, who took the helm last fall.

After a successful December concert in which 40 fourth-graders joined the chorale for a medley of Christmas carols, Zhou, 35, initiated another youth outreach program in January, inviting the county's top high school singers to perform at the Chorale's spring concert. Zhou selected Randall Thompson's "Frostiana," a 1959 choral work based on seven poems of Robert Frost, and John Leavitt's "Requiem" for the program.

"I was really excited," said Ryan McGuire, 16, recalling when she learned about the opportunity from her choir director at Heritage High School. "We did 'Frostiana' and the All-District audition piece was a selection from "Frostiana" two years in a row, so I knew a couple of measures of two songs."

McGuire, an alto, e-mailed Zhou, who invited her to attend the next rehearsal. All the other students who had expressed interest had successful auditions for the All-State Choir -- whose performances conflicted with the spring concerts.

As a sophomore, McGuire was too young to audition for All-State, so she ended up as the sole delegate to the chorale from the county's high schools. She said it was awkward at first because she didn't know anybody in the chorale or its protocol. But she kept attending the rehearsals and soon found her niche.

"I just really love to sing, and I'll just sing anywhere where they'll have me, so I don't see this really huge achievement or anything," said McGuire, who sings in two of her school's choral groups, the select mixed choir and the after-school vocal jazz ensemble. She plans to return to the Loudoun Chorale in the fall and aspires to attend Shenandoah University to major in vocal performance.

After working with the chorale, all three students noticed improvement in their voices.

"I've learned that I do have a good voice and should be more confident with it," McConnell said. McGuire said it "improved my musicianship and made me a more confident singer."

All three have "been wonderful," Zhou said. "And there are many young adults, high schoolers, teenagers out there just like that. So we want to give them an opportunity."

Zhou said he'll offer the youth outreach program again next year. The chorale plans to record its first CD in the near future and eventually embark on a national tour.

For now, though, the chorale is on summer break until rehearsals resume in late August.

"I'm just really looking forward to whatever we're doing, because I know it's going to be great," said McGuire.

Loudoun Chorale music director Tianxu Zhou coaches Cecelia Osowski, Ryan McGuire and Patrick McConnell. Osowski, 15, above, is the youngest of the chorale's 60 members.