The technology Mark is using is a Soundbeam. It is the creation of a British composer, Edward Williams, and has been introduced into workshops for the disabled by a rock musician, David Jackson. Mr Jackson, who was a member of the Seventies band Van Der Graf Generator, will soon begin teaching formal music lessons in the use of the Soundbeam at Mark's school, Meldreth Manor School in Hertfordshire.
The Soundbeam works by the pupils breaking an ultrasonic beam by the often random movements of their hands, feet and even heads. It is a hi- tech development of an instrument invented in the early years of this century by a Russian, Leon Theremin. This created a kind of trembly noise, much used in Hammer horror films and most famously at the beginning of the Beach Boys' "Good Vibrations". It works on the same principle as the echo-location used by bats and dolphins.
The Soundbeam looks like a microphone on a stand and the children at Meldreth - most of whom are confined to wheelchairs - are positioned in front of it. The sounds they create through movement are translated back into a synthesiser or keyboard, which is pre-programmed with a series of scales. It means that children such as Mark, who before could only shake a tambourine with a teacher's help, can now play the most extraordinary and intricate tunes.
Two Soundbeams, which cost up to pounds 1,000 each, have been bought, and up to eight pupils, who staff believe will benefit most from the technology, will start formal music lessons in September.
In the spring the school is aiming to bring in pupils from nearby mainstream schools so that the disabled children can teach the able-bodied ones how to use the Soundbeam.
Mr Jackson said that the Soundbeam had given the disabled children a sense of achievement for the first time. He said: "The project is all about `that was me!' It's so rare that these children can achieve anything for themselves. People do things for them all the time and most of these children have to use a soundboard to communicate. But with Soundbeam they're controlling what's happening, they're making the movements which make the sound.
"When I first came to the school the children would make a movement and be completely amazed that they'd produced this beautiful sound. Then they'd make the movement again, and found they could make the same sound. This then became a huge learning curve for them, as they began to experiment with the sounds they could make with fast or slow hand gestures, or waving their feet."
The Soundbeams at Meldreth are programmed to reproduce a wide range of sounds, from drums to guitar to pan flutes. Most of the scales have been pre-programmed by Mr Williams but Mr Jackson has composed new sounds for the children. "The children recently gave a concert in the school grounds and I composed a special `Sea Tune'. Whatever movement one of the children made had the background of a harp, which sounded like the sea.
"The best way I can describe the effect is that one of the teachers said to me that Mark has completely changed since he's been working with the Soundbeam. He now has great confidence and he's increased his physical activity.
"When I first met him he was slumped in his chair. Now his hands are constantly moving, and he wants to communicate. I think it has unlocked him."
Until the Soundbeam was introduced, the only instruments the children at Meldreth Manor could play were simple ones such as the triangle and the tambourine. Music co-ordinator Rosemary Wallace said: "Before, we were doing traditional-type music. Because many of the youngsters have so little movement we were playing the triangle, tambourine and instruments like that by holding them with the children. This is a different form of communication. I've seen pupils who were previously very withdrawn suddenly open up when they find they can produce these wonderful sounds on their own." The Soundbeam has many other applications. Mr Jackson has been working with dance projects for able and disabled children, who dance in front of the beam to create sound through their movement. He says the possibilities of such a system are endless, in mainstream as well as disabled schools, especially through the medium of dance. While I was in the music class at Meldreth, one of the most severely disabled pupils, Martin, reached over to me. He wanted to tell me something using his soundboard. With the help of his teacher, he moved his hands to different symbols. "This music makes me happy," he spelt out.