Although most people don't think too much about the tick-tocking sound of their car's turn signal, Mary Jo Hlavaty's mind immediately begins creating new tap-dancing steps and rhythms when she prepares to make a turn or change lanes.

"I hear taps in the car, in the grocery aisles, everywhere," said Hlavaty, 40, of Colmar Manor. "Even when you're doing other people's pieces, tapping feels like a real creative process because their dances go through your body. It's energizing."

Hlavaty's passion for the often graceful and sometimes dramatic twists, turns and other movements accentuated by toe- and flat-footed tapping is matched by the 13 other members of the Step Aside Tap Company.

Based out of the Knock on Wood Tap Studio in downtown Silver Spring, Step Aside is an advanced group of tap dancers ranging in age from 19 to 48 who will perform an "Evening of Percussive Dance and Music" Saturday at Joe's Movement Emporium in Mount Rainier.

Members of Step Aside double as tap-dance teachers, parents, computer specialists, research assistants and Web designers.

On occasion they collaborate with the children's tap group that shares their studio space, Tappers With Attitude. Step Aside's routines cover an array of styles, including traditional a cappella tap dances and dances set to classical, jazz, blues, hard rock, hip-hop and funk music.

"One of our dances is set to the Beastie Boys, and another is a classical piece to Handel's 13th concerto -- you rarely see anything like it," said Shawna Frey, 32, director of the group.

Established in 1995, Step Aside is an auditioned repertory company whose mission is not only to experiment with new types of music and tap-dance techniques but also to provide training and performance opportunities for its members, most of whom have danced throughout their lives and are at the advanced professional level.

Step Aside recently performed at the 2002 New York City Tap Festival at the Duke on 42nd Street Theater. The group often entertains audiences throughout the metropolitan area, splitting time among the District, Montgomery County and Prince George's County. Frey said that starting with the Mount Rainier show, the group plans to become even more active in the Prince George's arts community because half of the group lives or works there.

Elizabeth Haverstick, 21, a math teacher at Eleanor Roosevelt High School in Greenbelt who lives in College Park, said that since she started taking classes at the studio almost two years ago, the group has increased its performance load and has begun to bring in choreographers from New York.

Drawn to Knock on Wood because it's an all-tap studio, Haverstick said she is glad to be surrounded by skilled dancers and hopes the company "spreads this form of dance and shows everybody the power of the dance and its meaning."

"I really thought that after a certain age, you were supposed to stop performing and turn to teaching and being a ticket buyer," said dancer Lisa Swenton, 31, who lives in Germantown. She also teaches tap part time at BlackRock Center for the Arts and works for Threshold Services, a nonprofit for adults with mental illness.

"Working for a mental health organization, this is my therapy," Swenton said. "It's rhythmic, based on jazz music, and not a mainstream, showy style of tap. You're not going to get what you see at your kid's dance recital when you watch us perform."

Tap dancing remains a powerful and mysterious force to some members of Step Aside. Carla Jenkins, 25, a researcher from Laurel who is also an instructor at the studio, finds solace and peace in tap dancing.

"Some people go to church. I tap. For me, it fills my soul," Jenkins said. "A lot of times your work environment is chaotic, or just the world, period. But no matter what happens, you can still hear the taps."

Step Aside Tap Company will perform with Knock on Wood Tap Studio and Tappers With Attitude at 8 p.m. Saturday at Joe's Movement Emporium, 3802 34th St., Mount Rainier. Tickets are $12 for adults, $10 for students and $6 for children 16 and under. On Sunday, free master classes for beginners and experienced tappers of all ages will be held at the same place 1-3 p.m. 301-699-1819.

Step Aside also will perform and hold an open dance and jam at Knock on Wood Tap Studio's "Open Mike Night" on Dec. 7. Knock on Wood Tap Studio is at 8700 Georgia Ave., Silver Spring. Cost is $7. 301-495-0395.

Tamara Henry, in white shirt, leads members of Step Aside Tap Company in rehearsal at Knock on Wood Tap Studio in Silver Spring. The troupe will perform Saturday in Mount Rainier. Below, the shoes that make the beat.