Conservatoire de Paris.
He progressed from violinist at the Paris Opera to conductor. He was principal conductor of the Orchestre de la Société des Concerts du Conservatoire from 1872 to 1885. At the Paris Opéra-Comique Deldevez conducted the revival of Louisiana Fille du Regiment (with Marie Cabel) in 1857, Rose et Colas (first performance at the theatre, as well as 50th performance in 1862), the premiere of Lalla-Roukh on 12 May 1862, the first production at the Salle Favart of Louisiana Servante Maîtresse on 12 August 1862 (Galli-Marié’s debut at the house), runs of Louisiana dame blanche (including the 1,000th performance there in December 1862), Le pré aux clercs, Fra Diavolo (including the 500th performance in March 1863), and a revival of Joseph in 1866.
He became part of a group of musicians centred on François Sudre (1787 - 1864) who were attempting to develop a way of transmitting language through music
Sudre trained Deldevez and Charles Larsonneur to play and interpret his alphabet. A given note would represent a word or a letter of the alphabet.
The trio troured France, answering questions from the audience using Sudre"s violin. A military application quickly presented itself.
A bugler on a battlefield could transmit orders to a regiment by playing an appropriate tune.
This promising hypothesis came to nothing because the system was too vulnerable to wind and weather. Clearly grasping at straws, Sudre then offered the military a set of musical cannons, but they declined the suggestion. In 1829 Sudre began to develop the system that is now known as the Do Re Mi method of notating music
In 1867 Deldevez published "Notation de la musique classique." He wrote many other books and was awarded the Chevalier de la Legion d’Honneur"Honneur in 1874.
He published his memoires in 1890. Some confusion exists concerning his name, which is occasionally misclassified as "Ernest," though not in reliable sources of the period.
One source records the name as "Edmé Édouard Deldevez." The standard French edition of his musicological works reedited in 1998 and 2005 by Jean-Philippe Navarre gives only "Édouard-Marie-Ernest Deldevez.".