The festival, which takes place every three years, includes a competition and has continued to grow through the efforts of festival founder and director Robert Geary, event spokesman Scott Horton said.
This year, 670 children in 20 choirs, ranging in age from 8 to 18, are attending, marking the largest attendance in the event's history.
"For some of them it's a regular thing, and for others it's a great opportunity," Horton said.
Twelve countries will be represented at the event, including the Republic of Georgia, Canada, China, the Philippines, and Honduras.
There will be daily free public concerts at a dozen locations throughout the Bay Area, including Jack London Square and the Napa Valley Opera House.
The opening concert will be at 3 p.m. today at the First Presbyterian Church at 2407 Dana St. in Berkeley.
The Grand Finale Concert will be held on Saturday at Zellerbach Hall on the UC Berkeley campus at 7 p.m. Tickets must be purchased for this event, and information can be found at www.goldengatefestival.org.