The Velvet Tones are very much a senior citizen choir, with members ranging from 55 to 84 years old.

But don't let the words "senior citizen choir" color your perception too much: these folks know how to rock.

"People think we're going to come out and sing 'Little Brown Church in the Vale' to piano accompaniment," said Gary Anderson, president of the Velvet Tones choir, based in Apple Valley. "Then we come out and do rock 'n' roll with a sound system, and people are like, 'Holy mackerel.' "

The choir's opening number, for instance, is "Joint Is Jumpin' " by Fats Waller, a jazzy number that celebrates thumpin' pianos and rockin' roofs. Then they take it down a notch with the Gershwin classic, "They Can't Take That Away From Me." The heat picks up again with "And All That Jazz" from the musical "Chicago," with its sultry talk of wailing blues and rolled-down stockings.

A big favorite among the choir singers is the Johnny Cash anthem, "I Walk the Line."

"The men get excited and sing really loud on that one," said Mary Watts, a 10-year Velvet Tones veteran.

Part of the reason the Velvet Tones edge toward classic rock and saucy show tunes is simply a matter of time and space. The choir's youngest members were teenagers in the early 1970s. Even the Velvet Tones' eldest member -- age 84 -- was just 29 when a hip-shaking Elvis Presley appeared on the Ed Sullivan Show in 1956.

The other factor is Rich Clausen, the choir's director, who once traveled the country with the Swinging Ambassadors and took regular gigs at Diamond Jim's in Mendota Heights.

"I get to choose all the music, so obviously I choose music I like," said Clausen, 69, who has directed the choir since 2004 and plays seven different instruments.

Clausen's formula seems to be working. The choir was invited to sing during a 10-show Guthrie Theater performance of "My Father's Bookshelf" in 2009, and it's also performed at the MacPhail Center for Music in Minneapolis.

This year the choir added 14 new members, bringing its total to 74. That's a remarkable change considering the choir was launched just 13 years ago with 10 singers as a learning program through School District 196.

Each year, the choir performs about 30 shows, most of them requiring tickets. But this year, with a grant through the Metropolitan Regional Arts Council, the group is able to perform eight free shows. The next free performance will be at 7 p.m. Saturday at Eastview High School in Apple Valley. The concert will include singers from the Highland DaCapo elementary-age choir, as well as performers from the Monique School of Dance in Apple Valley. The event will be emceed by local broadcast personality Stan Turner.

"Come on out and watch us," said Gene Brandl, 66, one enthusiastic choir member. "We promise we'll knock your socks off."

Alyssa Ford is a Minneapolis freelance writer.