SAN FRANCISCO (Map, News) - The co-founder and artistic director of Ragazzi Boys Choir is celebrating the Peninsula group’s 20th anniversary. The boys’ final holiday concert is at 5 p.m. Sunday at the First Congregational Church, 1985 Louis Road, Palo Alto.

How did Ragazzi start? I had been an assistant with the San Francisco Boys Chorus for two years, and had been teaching at a Crystal Springs school [in San Mateo County]. A parent, Carolyn Watts, approached me about starting a group on the Peninsula.

How many singers are in Ragazzi? More than 150, in five different groups.

What’s on your holiday concert program? We’re calling it “Christmases Past” because it goes through the history of classical music, from medieval times on. A highlight is the famous “Ave Maria” by Franz Biebl. There also will be singalong Christmas carols.

What distinguishes Ragazzi from many other Bay Area children’s choral groups? We’ve got a pretty adventurous repertoire, including foreign languages and folk songs. We have the strongest changed-voice choir in the area.

Is it true the group won a Grammy? Yes, we sang with the San Francisco Symphony on its recording of Stravinsky’s “Persephone,” which won a Grammy. It was gorgeous music.

What positive effects does being in choir have on the boys who sing? It teaches them to become sensitive to beauty. It’s also active, yet slow. The singers have to think — and to delay gratification, which is hard.

What’s coming up for Ragazzi? We’ll be singing the world premiere of composer Ted Toews’ “The Emperor’s New Clothes” in San Mateo in April. —