The left hand, so often relegated to the accompanying chords and subservient to the melody being played by the right hand, would come into its own with the instrument. Mr Seed plans a complete mirror-image of an early 19th-century fortepiano: the highest notes will begin on the left and the lowest ones will be found on the right. The pedals will be reversed and,if playing with an orchestra, the soloist will be facing the other side, to ensure that his left hand and the lid are facing the right way. Musical scores do not have to be re-written because the treble clef will be played with the left hand. The fingering even remains the same.

Christopher Seed at an ordinary piano. His design for left-handers is based on a mirror-image of the fortepiano

Mr Seed,who is left-handed, proved that it could work by programming his electronic keyboard. "I realised how easy it is to adapt. I thought it would take years to retrain, but within a day I was reading Mozart backwards. It improved my playing and seemed so natural." Mr Seed, 32, has given recitals at the Wigmore Hall and St.John's, Smith Square. He teaches at Winchester College.

In most piano repertoires, he explained, the proportion of right-hand notes to left- hand ones was unbalanced. He has long avoided Chopin and Mozart for that reason. He said his design could also be useful for right-handed players who wanted to strengthen their left hand.

Peter Dickinson, professor of music at Goldsmiths college, University of London, said the idea was "revolutionary. He said music was generally "written with the right hand dominant", apart from ragtime and certain kinds of jazz.

Stanley Sadie, editor of The Grove Dictionary of Music and Musicians, said assessing which composers and performers had been left-handed was difficult: many may have suppressed their natural preference because being left-handed was long considered sinister. But C.P.E. Bach was a likely candidate, judging by an oblique reference by his father J.S.Bach, to his son having to strengthen his right hand.