Wrapping up their 49th year as the elite choral group at the regional high school, the Minnesingers drew packed houses for their winter concerts Friday and Saturday. All ages shared the pews at the Old Whaling Church in Edgartown, from senior citizens to small children on their best behavior.

Elite high school choral group is about to enter its 50th year. — Maria Thibodeau

The Minnesingers shared the stage as well, with a series of special guests that began with the West Tisbury bell choir and included singers, guitarists and even a saxophone player. Led by director Janis Wightman, the program was a party mix of traditional, popular and modern holiday music showcasing the choir and their guests.

Singing from behind the back row — an unexpected treat for latecomers who couldn’t get seats any closer to the stage — the Minnesingers opened their concerts with Fanfare for Christmas by the late Lloyd Pfautsch, a longtime professor of choral music at Southern Methodist University. Then, as organist Peter Boak and trumpeter Oliver Hughes joined in from the loft, the 29-member choir made its way to the front of the church singing Hark the Herald Angels Sing.

The bell choir’s nine ringers awaited them on stage and the combined groups performed contemporary British composer’s John Rutter’s joyous carol All Bells in Paradise, with Minnesingers accompanist Nancy Rogers on piano. A 16th-century motet by Spanish composer Tomas Luis de Victoria was next, as the bell ringers discreetly packed up and left with their gear.

The next guest on the program, Mark Lovewell, stopped the show on Saturday before he even began to perform. Stepping on stage with his acoustic guitar, a harmonica braced to his neck, he announced “I’m going to say what everybody’s thinking right now,” before turning to the choir and saying it:

“Aren’t we lucky to have you?”

Singer Mark Lovewell wowed the crowd with guitar/harmonica rendition of Silent Night. — Maria Thibodeau

As an explosion of audience applause subsided, Mr. Lovewell went on talking to the Minnesingers, praising their hard work in meeting the challenges of choral singing.

“You inspire us. You make us a better community,” he said.

Mr. Lovewell’s performance with the choir, Silent Night, was one of the evening’s standouts. Singing in a strong, clear tenor or blowing the harmonica as he picked his guitar, Mr. Lovewell stirred memories of folk music’s golden era in the 20th century — especially when he invited the audience to sing along.

Other guest performers were saxophonist and Minnesingers father Steve Tully, who joined the choir for Leroy Anderson’s light-hearted Sleigh Ride; son and mother Willy Mason and Jemima James, who sang O Little Town of Bethlehem with Mr. Mason on guitar; Siren Mayhew, singing a pensive Have Yourself a Merry Little Christmas and Merrily Fenner, on guitar and voice, with a sly and sultry Santa Baby backed up by the male Minnesingers.

After intermission, the mostly-Minnesingers male a cappella group Soundwave took the stage, with alumnus Jared Livingston joining his former bandmates at Saturday's performance for White Christmas. Soundwave’s rendition of the Justin Bieber holiday hit Under the Mistletoe, with soloist Jaden Edelman, drew some of the evening’s most enthusiastic applause.

Saturday afternoon concert saw a special guest. — Maria Thibodeau

Other concert highlights included Christmas Star, a carol by celebrated composer John Williams which the choir sang while rendering the lyrics in sign language and a zany medley, arranged by the innovative a cappella group Straight No Chaser, that began with The 12 Days of Christmas and veered through several other holiday songs — including I Have a Little Dreidel — before concluding as Toto’s Africa.

With more than 20 songs on the program — and a fly-by visit from Santa Claus that involved inviting some two dozen Santa-struck children onstage for Jingle Bells — Ms. Wightman and the choir kept a brisk pace and finished the concert in just under two hours, including the 10-minute intermission.

The finale, another Minnesingers tradition, was the Hallelujah Chorus from Handel’s Messiah with all former Minnesingers in the audience invited to come onstage and join in. Mr. Hughes the trumpeter, Mr. Livingston the recent graduate and more than half a dozen other Minnesingers alumni accepted the challenge, with Mr. Boak’s organ thundering in support as nearly everyone in the audience came to their feet for the triumphant chorus.

And even then, the singers weren’t finished. With Ms. Rogers at the piano, they sent the audience on its way with a sassy, boogie-woogie arrangement of Santa Claus is Coming to Town.

The Minnesingers celebrate their 50th anniversary in May with concerts that will also feature alumni. The shows will be Ms. Wightman’s finale with the group, as she is retiring at the end of the school year.

See more pictures of the Minnesingers here.