Tod Machover is a kid at heart. Even his flyaway hair looks wired.

In workshops to help create his "Toy Symphony," he impishly crouches on the floor with little kids, joining them in playing with the gizmos in the Children's Museum. You should see him make ping-pong balls dance on currents of air. But "Toy Symphony" is not child's play.

Machover also spends his time hovering over computers and working with the sophisticated musicians and technicians from MIT's Media Lab to create this vast educational and artistic project. It culminates Saturday in the sold-out American premiere of a concert that has already generated excitement when created and performed in Berlin, Dublin, and Glasgow.

The purpose of the creators was serious - to empower children with music - but it's clear everyone approached the adventure with a sense of fun and delight. The result will bring both the professional musicians of the Boston Modern Orchestra Project and children to MIT's Kresge Auditorium tomorrow night at 7.

Machover won his spurs at IRCAM, Pierre Boulez's center for advanced musical explorations in Paris; from 1978 to '85 he was its director of research. Since 1985, he's been in residence at the Media Lab, where he is professor of music and media and director of the Opera of the Future project.

Through the years he has been particularly interested in the ways in which electronics can extend the expressive possibilities of acoustic instruments. With his colleagues Machover has invented several "hyper instruments" (violin, viola, cello, guitar) and has written music for them to play.

Machover is the father of two children, Hana, 9, and Noa, 5, and parenthood led him to an interesting observation.

"When a child is only 2, we give him or her colored paper and glue and maybe even scissors and encourage them to put them together to make something," he explains. "We ask them to tell stories, even though they cannot read or write yet. We don't do that in music because we think it requires technical knowledge or mastering the mechanics of an instrument. Yet children take more quickly to things they can do with their voices and hands than they do to visual things."

Deciding to change this pattern, Machover and his team created three new music "toys." Two are musical instruments called "shapers" and "beatbugs." These are mostly aimed at children, ages 5 and older. The third toy is a computer program, Hyper score, that enables slightly older children and adults to compose music using graphics rather than conventional musical notation. Machover calls these inventions "training wheels" for young musicians.

A shaper is a squishy object, a little bigger than a softball, covered with colorful patchwork cloth. Pressure from the fingers as a child pushes, pulls, squeezes, and kneads the shaper influences a musical phrase or gesture. The shaper controls speed, timbre, dynamics, and structure. It creates musical shapes "like a conductor," Machover observes (but don't try squeezing a conductor).

"What I like about the shaper," says tiny Ebony Beech from Dorchester, is all the different sounds I can make with it." Beech will be in the group of shaper players in Saturday night's concert.

Beatbugs are percussion instruments that look like giant computer mice, equipped with flexible antennae. One of the antennae controls timbre; the other can build the rhythms a child beats onto the instrument's surface into more complex patterns.

Like real insects, beatbugs communicate with each other and influence each other's patterns; rhythms can jump from one beatbug to another. Beatbugs can duel, or they can create conversations that fly off in unpredictable directions.

Austin Richard Linehan, 10, from South Boston, calls his beatbug "really cool" because of "the sounds it can make. And because we can play to each other."

Using Hyperscore, a budding composer can create melodies, choose harmonies, build counterpoint, orchestrate colors, and control tempo and dynamics by drawing lines of various colors and shapes across the computer screen. The computer can then "perform" the piece - or print it in conventional notation for traditional instruments.

One composer, Victoria Conrad, 12, of South Boston, collaborated throughout the project with her friend Kristine Mullen, also of South Boston. She followed the example of Bach and Shostakovich by composing her own name into her piece. Part of her graphic design is a large and elaborate "V."

Hyperscore would be a cumbersome tool for writing down a fugue in the style of Bach, but it does allow a youthful composer's imagination and fantasy to develop and roam - and it's fun for anyone to play with. And the previous "Toy Symphony" events in Europe prove that very deft and entertaining pieces can be composed on Hyperscore.

A project for everyone

Each "Toy Symphony" concert begins with extensive Hyperscore workshops. In Boston, five branches of the Boys and Girls Clubs hosted them over several weeks; students and research associates of the Media Lab came once a week to help more than 40 kids with their compositions. Each day culminated in a "concert" in which the composers played their pieces for each other.

Each group sent at least one participant to a further set of workshops at the Media Lab where nine kids worked daily, one-on-one, with Machover and his team to produce new pieces - some of which will be performed in Saturday's program.

"My vision from the beginning," Machover says, "was to put something on where it would feel natural to have people of different ages and levels of skill come together onstage. I didn't want to create a project for genius kids; I wanted to let everyone in and to create a situation where it was natural for many different layers of activity and expression to come together."

Two of Machover 's own compositions frame the concert program. Leading off is a piece called "Sparkler," which doesn't involve the participation of children. "It's an overture," Machover says, "about what the orchestra of the future might sound like, and it refers both to Beethoven and to the Beatles."

Most of the piece is meticulously notated, like music of the past; there are also passages Mach over calls "texture blobs" that send the sound of the orchestra into the computer and out, transformed.

And at the end stands Machover 's actual "Toy Symphony," a work in two movements, "Lullabye" and "Chorale."

An electronically enhanced violin, the Hyperviolin, joins the professional orchestra and children who both sing and play the music toys.

"The chorale is a quiet piece that brings all the forces from the rest of the concert together, and the melody comes from `Sparkler' back at the beginning," Machover says.

The classical musical world was resistant to "Toy Symphony" at first; it was too new. Gil Rose and the BMOP took up a challenge that America's major orchestras decided to pass on.

"Most of the big American orchestras have education programs in place already and feel the area is covered," Machover says. "I think the most important thing an orchestra can do is not to teach the classical repertoire but to use its resources to teach music and creative music-making."

Future performances of "Toy Symphony" will take place in New York and Tokyo, and now that the work has proved successful in Europe, Machover says invitations are "pouring in" to bring the work elsewhere. He needs to decide how much more time he and his colleagues should invest in it - and he's pleased that in Berlin Kent Nagano is already continuing the "Toy Symphony" work without the direct participation of the MIT team.

Machover himself is interested in developing a comparable project for children up to the age of 5.

"We know that children of that age are both imaginative and needy, and one way to help them fall in love with music is to help them become composers. The earlier you start with music, the more natural the connection is. And I am partial to music - it trains all the intellectual faculties; it is the activity that exercises the most parts of our being, everything physical and emotional, and it pulls those parts together."