Published: November 9, 2013 | Last Modified: November 9, 2013 01:30AM

WALLINGFORD — Adam Romo, musical director of El Mariachi Mexico Antiguo, a professional mariachi band from Las Vegas that is composed of members aged 15 to 23, listened as members of the Spanish Community of Wallingford’s Mariachi Academy performed “La Negra,” a standard of the genre.

After hearing the students play the piece as an ensemble, Romo divided them into groups by instrument for individual instruction. Three of the professional band members worked with students who play the flute, guitar, and guitarron — an oversized, Spanish guitar — while Romo worked with the trumpet section.

Romo and his students came to Wallingford at the request of SCOW Music Director Evangeline Mendoza, whom he met at a mariachi conference. They arrived Thursday for three days of teaching sessions with Academy students.

Guitarist Samantha Lopez, 16, said the professional musicians are helping her and her peers learn new playing techniques and hand positions, as well as  “perfecting what we already know.”

The players are also teaching them to play songs by ear instead of relying on sheet music, said 17-year-old guitarron player Eliel Martinez.

Mendoza said the visitors are also teaching her students how to play notes in a traditional mariachi style. “These details are so important,” she said, as she watched members of the band hone her students’ techniques.

Romo said he was impressed by Academy students’ grasp of mariachi music and tradition. He said he and the members of his band were simply “helping them with the details and filling in the gaps” in their mariachi learning.

Jose Luis Robles, 19, who taught the Academy’s guitar students, said he recalled the difficulty of mastering lessons that Academy students are now trying to learn, such as proper pick position, correct posture, and maintaining tempo. “I definitely see a younger version of myself” in them, he said.

Nineteen year-old Rodbel Virula, assistant director of El Mariachi Mexico, worked with the Academy’s guitarron players and observed that he was familiar with their learning experience.

“They’re struggling with the same things I struggled with” because they lack individual mariachi instrument teachers, just as he did, he said.

Mendoza is in charge of SCOW’s music program, including the Mariachi Academy, but she does not provide instrument lessons.

Violinist David Cervantes, 16, praised the Academy students for “having learned so much by themselves.”

Mendoza said it was invaluable for her students to see and hear peers in their own age group, such as Cervantes, “perform at the same level as adult musicians.”

She was also thankful that Romo and his contingent were willing to spend three days working with her students, unlike mariachi musicians from the east coast whom she has enlisted in the past who have only been available for an hour or two, she said.

The group began their stay with an initial four-hour practice session at SCOW on Thursday, followed by a dinner with some of the students, parents, and SCOW board members.

The band performed at a coffee house at Choate Rosemary Hall on Friday morning and then returned to SCOW for four more hours of musical instruction.

Today, the group will conduct a final five-hour clinic with Academy students, before joining them for a combined performance at 4 p.m. The joint performance will be followed by the band’s own independent concert.

Both events are at SCOW and open to the public.