One of the oddest musical inventions of the 20th Century is the electronic instrument known as the ondes martenot, invented in 1928 by Maurice Martenot.

Its performer sits at a keyboard, which is played with the right hand, the keys being capable of lateral movement to produce vibrato, while the left hand operates a set of potentiometers to produce changes in timbre and dynamics.

All sorts of strange swoopings, shimmerings and glissandi can be produced out of the contraption's speakers.

Jeanne Loriod became fascinated by the ondes while a student in Paris.

After studying with Martenot himself, it was she who developed the instrument's full potential, wrote the standard work on its use and later taught it to others.

Her elder sister, the pianist Yvonne Loriod, married the French composer Olivier Messiaen and the two sisters often appeared in his mighty Turangalila Symphony (1948), which features a prominent ondes part specially written for Jeanne.

Jeanne Loriod died last year, aged 73.

-Roger Moodiman, Marine Parade, Brighton