Welcome to the world premiere of the grandest symphonic fresco yet by Mason Bates, a Bay Area composer who also spins platters in the sizzlingest local discos. Co-created with the filmmakers Gary Rydstrom (writer/director) and Jim Capobianco (story artist/animator), the 25-minute adventure—subtitled The Making of the Orchestra—celebrates the centennial of the Chicago Symphony Orchestra’s concerts for children (the Chicago performances, conducted by Edwin Outwater, take place during the school day). The stated purpose of the piece is to take audiences inside the instruments of the orchestra to reveal how they work. A 21st-century American answer to Benjamin Britten’s still delectable Young Person’s Guide to the Orchestra? Heaven knows, we could use one. A reprise, for grownups, follows April 16 to 18 on the composer’s home turf, with the San Francisco Symphony. Why should kids have all the fun? (Or all the educational opportunities?) —M.G.