Of all the musical instruments the first- and second-grade students at Thetford Elementary School played after school last Wednesday, their preferred instrument seemed to be their own voices.

After a long school day, running around and being noisy was top priority for a group of students in the inaugural session of the Thayer School After School Science and Engineering program in Thetford. So to start, Valerie Hanson, a Thayer master’s degree student, introduced the youngsters to their own musical instruments by having them place their fingers on their necks and hum.

“Do you feel it vibrating?” she asked. Those were the molecules moving around to create a sound, she explained.

Better yet, “we’re going to make our own type of musical instrument,” Hanson told the students. Knowing both the energy level of the children and their propensity for making noise, Thayer students came prepared with rubber bands, red Solo cups and popsicle sticks for the students to create makeshift kazoos and guitars — rudimentary instruments, to be sure, but they would help them understand why, for example, a guitar has strings of different widths.

An extracurricular science program, held in the after-school hours when some students want nothing more to do with learning, may not strike one as an especially popular way for elementary schoolers to spend free time. Yet when word got out about the program at Thetford, “there was a stampede of interest,” said Pam Podger, a Thetford Elementary parent who helped bring the program to the school.

The Thayer program had immediate appeal for Podger, who first learned about it when she accompanied a robotics team from Thetford to the First Lego League competition held last fall at Thayer. Knowing the elementary school was placing emphasis on so-called STEM (science, technology, engineering and math) education, “We thought, Our kids love science, love building things. Let’s bring it up here and see what happens,” she said.

It turned out that 50 Thetford students were ready to give after-school science a go. But for the first session of after-school science at Thetford, organizers decided to limit the number of students to just 13 in the first and second grades, so Thayer students could work with a manageable number.

The theme of the science program changes from week to week, but there’s an emphasis on teaching via the inquiry method, which encourages students to come up with their own hypotheses for the scientific quandaries they encounter. Last Wednesday, Hanson held an electric guitar in front of the students and began plucking its strings, asking them what the difference between the strings were. It took a few guesses, but one student observed that some strings were thinner than others. “They all make different sounds,” said first-grader Jack Cramer. Working together, the students concluded that the thinner strings produced higher notes.

Trying out chemical reactions on her own was what sparked Hanson’s interest in science at a young age. “I was always in the backyard, building things. I had more tools than my dad by the time I was 12,” she said. In working with students at Rivendell Interstate School District schools and Thetford, Hanson and other volunteers have tried to instill an understanding of science by having them build different items. In the first week of the program at Thetford, the students built their own batteries to power light bulbs.

“When they can see something happening or hear something happening,” Hanson said, children can the rules of science better than if they were reading a textbook or watching a teacher perform a demonstration.

To create the kazoos, every student received two popsicle sticks, and wrapped a rubber band around the length of one, then inserted plastic straw pieces between the two sticks. They affixed the second popsicle stick by wrapping a rubber band around the width of both ends.

“That looks good,” Hanson said to second-grader Madelyn Durkee. “Try it out and see how it works.”

Nearby, Durkee’s classmate Kway Antwi was giving his own kazoo a try. “That was Twinkle, Twinkle, Little Star,” he said, before launching into a rendition of the Alphabet song. Around Antwi, his classmates blew sounds both familiar and indecipherable into their kazoos. Hanson decided to get the group to perform in a more cohesive manner.

“Instead of making random noises, we’re going to make certain sounds,” Hanson said. She turned to second-grader Addy Holzer. “Addy, do you have a favorite song?”

“Happy Birthday!” Holzer said. With Thayer school employee Christian Ortiz singing the lyrics to the song, the first- and second-graders blew into their kazoos, until they had the hang of the familiar melody.

By giving students a chance to build everyday objects and helping them discover the science behind them, the organizers of After School Science and Engineering hope to help young children develop a desire to pursue one of the STEM fields. More than anything, they want to see students get excited about science the same way they do about recess.