CAMBRIDGE - Tod Machover may have composed more ambitious music than "Toy Symphony," but he will never engage in a more important project.

"Toy Symphony" is a concert that is the climax of weeks of process in each city where it is performed, and the process is revolutionary: It teaches very young children that music is not just something to listen to, but also something to play and even create yourself. The means for doing this are new "music toys" invented in MIT's Media Lab - the beatbug, a percussion instrument developed by Gil Weinberg and Roberto Aimi; the shaper, which controls other musical parameters such as speed, volume, phrasing, and color (developed by Aimi, Tristan Jehan, Maggie Orth, and Hugo Solis); and Hyper score, a computer program that makes it possible to compose music by moving colors and graphic elements around a screen (Mary Farbood and Egon Pasztor designed it).

More than 100 lucky children from the Boys and Girls Clubs of Boston and the Children's Museum have attended "Toy Symphony" workshops, and 15 of them participated in Saturday night's concert.

Machover proved an amiable and informative host, introducing each of the works and performers. He composed the two framing pieces, "Sparkler," an overture that opened the program, and the "Toy Symphony" itself at the end.

In between came two pieces featuring the shapers and one for the beatbugs, as well as three Hyperscore compositions transcribed for string orchestra. The first shaper piece, two movements from Jean-Pascal Beintus's "Nature Suite," added outdoor sounds to a John Williams-derived orchestral score ("Son of Harry Potter") handsomely played by the Boston Modern Orchestra Project under Gil Rose, a hero of the evening.

"Gestures," written by the gifted 12-year-old Natasha Sinha of Milton with MIT's Solis, was more interesting - a texture piece for onstage shapers and live instruments spaced around the auditorium, although the shapers were so hard to hear that one wondered if all of them were working. Gil Weinberg's "Nerve" for six children, two adult percussionists, and eight networked beatbugs brought down the house with sheer rhythmic exhilaration.

The pieces by the Boston children were "Times Change," by Leonardo Tanenbaum-Diaz; "Teyanna's Tunnel," by Teyanna Powell-Hughes; and "Passionate Schizophrenic," by Joshua McLellan. Each reflected the sound world that today's children live in, but each also exhibited an individual personality; none was afraid of dissonance.

Machover 's overture mediates between Beethoven and the Beatles. The "Toy Symphony" presents a "Lullaby" and "Chorale" linked by the same melody, and brings together beatbugs, shapers, a "Hyperviolin" soloist (the Irish violinist Cora Venus Lunny), the PALS Children's Chorus, and the orchestra. It turns into a vast, celebratory ode to the joy of music and its power to bring young and old together, diversity into unity.