This video is part of "Stepping Up," a short video series featuring four impressive young people working for change in their communities and explaining what sparked them to action. Watch all four videos here.
For Walter Diaz, the message is in the music.
Amid heightened fears of federal immigration crackdowns that rattled undocumented communities after Donald Trump's unexpected election victory last November, Diaz took action in the most effective way he knew how.
Then a senior at Lincoln High School in San Francisco, the 19-year-old immigrant from El Salvador started a Latino marching band with his classmates.
Throughout the school year, Diaz developed the sprawling band, leading it on occasional marches through the long hallways of his school, culminating with performances in the main courtyard. As they played Latin-tinged melodies, band members proudly donned flags of their native countries, held pro-immigrant placards and passed out fliers to fellow classmates about immigration resources and legal rights.