With 29 girls gathered around her, Katie Anderson lifts the pitch pipe to her mouth, signaling the beginning of the song. With a swift wave of her arm, the girls jump into an a cappella rendition of “Man in the Mirror.”

The performers are members of Duxbury High School’s very first all female a cappella group, Here Comes Treble. The group was started in November, after years of interested students tried unsuccessfully to find a leader. This year, they found their leader in Anderson.

This is Anderson’s first year teaching full time at Chandler elementary school  and when she was approached by some interested and ambitious students, she jumped at the chance to help get the group off the ground. The group is a non-audition group, so any student who wants to join is welcome.

Anderson graduated from Wheaton College in 2010, where she was the music director of Norton Youth Theater and the Wheaton Whims a cappella group. After graduation she taught a cappella in Dorchester to high school students before coming to teach in Duxbury full time.

“The girls are all very talented,” Anderson said. “They have two songs so far and they are doing very well.”

Here Comes Treble has been rehearsing twice a week and Anderson said she has revved up rehearsals to a higher intensity in anticipation of the upcoming show, Amazing A cappella.

Alenni Davis, a senior, said she is a long-time fan of the Pacmen, the male a cappella group at the high school, and was “all ears” when the possibility of a female group became a reality.

While Davis began singing just a few years ago, she has ten years experience playing piano, viola and guitar. A member of the string ensemble, pep band and full orchestra, Davis was recently accepted into the All State Orchestra. So far, she has enjoyed her time with the group.

“Ms. Anderson is the best mentor and leader any of us girls could have possibly hoped for,” Davis said. “We have all bonded over our mutual love of singing and music, and that bonding makes singing together a blast.”

Anderson said the group is a dynamic collective of students with many different interests and talents. Students in the group range from the lead in the school musical to taking music lessons outside of school to non-music activities.

Janine Neprud, a junior, said she was excited to have the chance to perform with the female a cappella group. Neprud has an ear for music, as she has taken voice lessons for a few years and has played the flute, piccolo and piano for a number of years.

“The experience has been amazing,” she said. “There are so many incredible voices in the group and we all work together so well.”

Neprud said her favorite part of being in the group is seeing how the parts of the songs fit together and how each student has a different way of contributing to the group.

“I’m looking forward to getting up in front of the audience at Amazing A cappella and performing with my friends,” she said. “Showing everyone the result of all our hard work is always fun.”

After Amazing A cappella, the group looks forward to traveling down to Disney for the school music trip to perform alongside the boys a cappella group, the Pacmen. As far as the repertoire for that performance, Anderson hinted at possibly learning some Disney tunes.

Anderson said she is surprised by the girls’ talent.

“I didn’t know what to expect or how they would handle starting a group from scratch, but they really get it,” she said. “They surprise me at every turn; they take on every challenge I give them and show me they are ready for it.”

Davis said Anderson encourages the students to try hard and do their best and provides them with a comforting, loving environment. As part of the group, Davis said she is impressed by how well the voices blend together.

“Every girl in the group brings something unique and beautiful into the group, creating a mixture of various, brilliant talents,” she said. “We have girls who have smooth, light voices, are powerhouses, who arrange their own versions of popular tunes and even girls who can beatbox.”