As Herrera entered a class at John Hancock College Preparatory High School, he was greeted by senior Daniel Luna, about 20 other students as well as a check for $1,000.
Luna had sent a video to the VING Project, a charity that helps teens recognize supportive people in their lives. In a 60-second video, Luna talked about Herrera, a teacher who for years has volunteered his time to teach music to students for free. Other teachers even call him a "living legend" who organizes open mic events in the neighborhood.
"I hope the money will help him be able to teach the students the way he wants ... with better instruments," Luna said in his video.
The name VING comes from the charity's mission to encourage teens who are "liVING" with purpose, believing in a brighter future and giving back to others. VING is aimed at teens, ages 14 to 18, who want to make a change in their community.
Each month, teens are selected from videos they send VING, in which they answer the question: "If you had $1,000 to give away, who would you give it to?"
"It kind of turns the selfie on its head," said Jill McClain, executive director of the VING Project. "Send us a video of yourself. ... But talk about someone in your life who really deserves this boost."
The money comes from an anonymous family in Chicago. So far, VING has given out more than 50 gifts across the U.S.
Today, students laughed and cheered as Luna presented Herrera with an envelope and thanked him.
"Is this for us to buy more guitars?" Herrera asked.
"This is for you, Mr. Gustavo," Luna said. "I chose you because you're so passionate and dedicated to teaching us -– everyone here and me -- to play guitar and all these instruments. I really appreciate that you dedicate your time and you spend your own money. ... I really appreciate it."