"We ask the families to come up with $500, because we teach that nothing comes free. So my students aren't just sitting and waiting for someone to give them something. They're working very hard."
It certainly looks that way during a rehearsal at Creative Arts, a public high school and middle school that's a magnet for talented kids citywide.
The place is alive with the sound of music being made in various classrooms. Students carry instruments and jam in the hallways; it's like Fame, or an urban version of Glee.
"Let me hear my wonderful tenors! All right, my beautiful sopranos!" exclaims Ortiz, 51. A diminutive figure, she stands at an electric piano, commanding the room, conducting the music, and listening.
About 20 girls and boys stand in a semicircle around the teacher, who combines a veteran musician's technique and a teenager's energy as she warms up the voices.
"Guys. We start forte," she tells a row of boys.
She likes what she hears.
"Bravo. Bravo. Bravo!"
Gospel choir director Benita Farmer, like Ortiz an accomplished musician and teacher, passes out the sheet music for "Sapientia IV."
It's part of a sacred song cycle written in Latin by Czech composer Jiri Teml. The strong, young voices seem at home in the language, just as the string quartet under the direction of Patricio Acevedo seems comfortable with its classical repertoire.
These kids are good.
Getting ready for Prague "is challenging, but it's a good experience for all of us," says tenor Bryan Marquez, 17, a junior.
Anthony Warren, 17, a senior, is "looking forward to being in the musical atmosphere. . . . Prague has a good reputation for classical music. And I love classical music."
The students are well aware they will have many eyes as well as ears upon them.