John Argosino is only 8 years old, and he composes piano music in a style somewhere between Mozart and Schubert. Kumi Yabuhara is 14 years old, and her piano music has a fiery, romantic, virtuoso style somewhere between Franz Liszt and Sergei Rachmaninoff.

Both young musicians were amazing this weekend at Wolf Trap, when they performed their own compositions during the International Children's Festival, but they are not really unique. They are part of a group of young prodigies systematically selected and nurtured by the Yamaha Music Foundation from a music education program that includes more than half a million students around the world, aged 4 to 15. Each year, about 20,000 pieces of music by young composer-performers are submitted to the foundation for possible use in the Yamaha Junior Original Concert festivals, and Argosino and Yabuhara are among those who were selected.

Each showed a distinctive personality as a composer and impressive abilities as a performer, not only in written-down works but in improvisations on themes submitted by members of the audience. For those who heard another group of young performers sponsored by Yamaha last April, when they played here and at the United Nations with the National Symphony Orchestra, the shock effect may have been less. And if Argosino's "Lost Galaxy" or Yabuhara's "Rhapsody" is compared closely with the music of the composers who clearly inspired these young musicians, the newer works may seem relatively simple and uninventive. But such comparisons are not farfetched, and the fact that this kind of music is being produced in significant quantities by children of this age group sets the mind reeling and raises enormous questions about traditional methods of music education.

The Yamaha children are not the only remarkable musical phenomena to emerge from Japan in recent years, but on first acquaintance they seem to be educated in a system more creative and flexible than the well- known Suzuki method. It will be interesting in the years ahead to see what permanent results emerge from this remarkable method of musical training.