French composer and pianist Maurice Ravel may have left a hidden message inside his work, according to a Ravel expert.

David Lamaze, a professor at the Conservatoire de Rennes in France, says Ravel inserted a sequence of three notes throughout his work, spelling the name of a Parisian socialite.

"It has never been done before. To take one person and to place them at the centre of a life-long work," says Lamaze told BBC Radio.

The notes E, B and A in a musical notation — which corresponds to the sound of "Mi-Si-La" in the French doh-re-mi scale — refer to Misia Sert, a close friend of the composer.

Sert was painted by Renoir and Toulouse-Lautrec. Ravel composed some of his work while staying on a boat belonging to Sert and her second husband. Sert married three times, while Ravel stayed single until his death in 1937 at age 62.

"To put the feeling of love at the very central point of the creation without us knowing it. That is typical of Ravel, I think," notes Lamaze, who believes Ravel was inspired by his love for Sert.

The Mi-Si-La sequence appears in key parts of La Valse as well as the start of the Viennese Waltz, according to Lamaze, who is writing a book about Ravel and Misia.

Lamaze says his book may put to rest speculation that Ravel was gay.

Ravel composed for the piano as well as for ballets and operas. His well-known pieces include Boléro, Trio and Daphnis et Chloé.